This PR includes backport of the regular version bumps and `prdocs`
reordering from the `stable2412` branch back ro master

---------

Co-authored-by: ParityReleases <release-team@parity.io>
Co-authored-by: command-bot <>

[polkadot-runtime-parachains] migrate disputes and disputes/slashing to benchmarking to bench v2 syntax (#6577)

[polkadot-runtime-parachains] migrate disputes and disputes/slashing to
benchmarking to bench v2 syntax

Part of:
* #6202

---------

Co-authored-by: Giuseppe Re <giuseppe.re@parity.io>
Co-authored-by: Bastian Köcher <git@kchr.de>

Linked to issue #590 
Extracted code from mod.rs to new tests, mock and benchmarking files

# Description

Linked to issue #590.
I moved the tests and benchmarking to their own seperate file to reduce
the bloat inside auctions.rs

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

Linked to issue #590 
I moved the mod, tests, mock and benchmarking to their own seperate file
to reduce the bloat inside purchase.rs

---------

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>
Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

Relates to: https://github.com/paritytech/polkadot-sdk/issues/6918

---------

Co-authored-by: command-bot <>

Linked to issue #590.
I moved the mod, tests, mock and benchmarking to their own seperate file
to reduce the bloat inside claims.rs

---------

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>

Migrates pallet-xcm benchmarks to benchmark v2 syntax

* Part of #6202

Adds a new zombienet-sdk test which verifies that elastic scaling works
correctly both with the MVP and the new RFC 103 implementation which
sends the core selector as a UMP signal.

Also enables the V2 receipts node feature for testnet genesis config.

Part of https://github.com/paritytech/polkadot-sdk/issues/5049

---------

Co-authored-by: Javier Viola <javier@parity.io>
Co-authored-by: Javier Viola <363911+pepoviola@users.noreply.github.com>

Bump `polkavm` to 0.18.0, and update `sc-polkavm-executor` to be
compatible with the API changes. In addition, bump also `polkavm-derive`
and `polkavm-linker` in order to make sure that the all parts of the
Polkadot SDK use the exact same ABI for `.polkavm` binaries.

Purely relying on RV32E/RV64E ABI is not possible, as PolkaVM uses a
RISCV-V alike ISA, which is derived from RV32E/RV64E but it is still its
own microarchitecture, i.e. not fully binary compatible.

---------

Signed-off-by: Jarkko Sakkinen <jarkko@parity.io>
Co-authored-by: Koute <koute@users.noreply.github.com>
Co-authored-by: Alexander Theißen <alex.theissen@me.com>

Approval voting canonicalize is off by one that means if we are
finalizing blocks one by one, approval-voting cleans it up every other
block for example:

- With 1, 2, 3, 4, 5, 6 blocks created, the stored range would be
StoredBlockRange(1,7)
- When block 3 is finalized the canonicalize works and StoredBlockRange
is (4,7)
- When block 4 is finalized the canonicalize exists early because of the
`if range.0 > canon_number` break clause, so blocks are not cleaned up.
- When block 5 is finalized the canonicalize works and StoredBlockRange
becomes (6,7) and both block 4 and 5 are cleaned up.

The consequences of this is that sometimes we keep block entries around
after they are finalized, so at restart we consider this blocks and send
them to approval-distribution.

In most cases this is not a problem, but in the case when finality is
lagging on restart approval-distribution will receive 4 as being the
oldest block it needs to work on, and since BlockFinalized is never
resent for block 4 after restart it won't get the opportunity to clean
that up. Therefore it will end running approval-distribution aggression
on block 4, because that is the oldest block it received from
approval-voting for which it did not see a BlockFinalized signal.

---------

Signed-off-by: Alexandru Gheorghe <alexandru.gheorghe@parity.io>

Related to https://github.com/paritytech/polkadot-sdk/issues/1797

# The problem
When fetching collations in collator protocol/validator side we need to
ensure that each parachain has got a fair core time share depending on
its assignments in the claim queue. This means that the number of
collations fetched per parachain should ideally be equal to (but
definitely not bigger than) the number of claims for the particular
parachain in the claim queue.

# Why the current implementation is not good enough
The current implementation doesn't guarantee such fairness. For each
relay parent there is a `waiting_queue` (PerRelayParent -> Collations ->
waiting_queue) which holds any unfetched collations advertised to the
validator. The collations are fetched on first in first out principle
which means that if two parachains share a core and one of the
parachains is more aggressive it might starve the second parachain. How?
At each relay parent up to `max_candidate_depth` candidates are accepted
(enforced in `fn is_seconded_limit_reached`) so if one of the parachains
is quick enough to fill in the queue with its advertisements the
validator will never fetch anything from the rest of the parachains
despite they are scheduled. This doesn't mean that the aggressive
parachain will occupy all the core time (this is guaranteed by the
runtime) but it will deny the rest of the parachains sharing the same
core to have collations backed.

# How to fix it
The solution I am proposing is to limit fetches and advertisements based
on the state of the claim queue. At each relay parent the claim queue
for the core assigned to the validator is fetched. For each parachain a
fetch limit is calculated (equal to the number of entries in the claim
queue). Advertisements are not fetched for a parachain which has
exceeded its claims in the claim queue. This solves the problem with
aggressive parachains advertising too much collations.

The second part is in collation fetching logic. The collator will keep
track on which collations it has fetched so far. When a new collation
needs to be fetched instead of popping the first entry from the
`waiting_queue` the validator examines the claim queue and looks for the
earliest claim which hasn't got a corresponding fetch. This way the
collator will always try to prioritise the most urgent entries.

## How the 'fair share of coretime' for each parachain is determined?
Thanks to async backing we can accept more than one candidate per relay
parent (with some constraints). We also have got the claim queue which
gives us a hint which parachain will be scheduled next on each core. So
thanks to the claim queue we can determine the maximum number of claims
per parachain.

For example the claim queue is [A A A] at relay parent X so we know that
at relay parent X we can accept three candidates for parachain A. There
are two things to consider though:
1. If we accept more than one candidate at relay parent X we are
claiming the slot of a future relay parent. So accepting two candidates
for relay parent X means that we are claiming the slot at rp X+1 or rp
X+2.
2. At the same time the slot at relay parent X could have been claimed
by a previous relay parent(s). This means that we need to accept less
candidates at X or even no candidates.

There are a few cases worth considering:
1. Slot claimed by previous relay parent.
    CQ @ rp X: [A A A]
    Advertisements at X-1 for para A: 2
    Advertisements at X-2 for para A: 2
Outcome - at rp X we can accept only 1 advertisement since our slots
were already claimed.
2. Slot in our claim queue already claimed at future relay parent
    CQ @ rp X: [A A A]
    Advertisements at X+1 for para A: 1
    Advertisements at X+2 for para A: 1
Outcome: at rp X we can accept only 1 advertisement since the slots in
our relay parents were already claimed.

The situation becomes more complicated with multiple leaves (forks).
Imagine we have got a fork at rp X:
```
CQ @ rp X: [A A A]
(rp X) -> (rp X+1) -> rp(X+2)
         \-> (rp X+1')
```
Now when we examine the claim queue at RP X we need to consider both
forks. This means that accepting a candidate at X means that we should
have a slot for it in *BOTH* leaves. If for example there are three
candidates accepted at rp X+1' we can't accept any candidates at rp X
because there will be no slot for it in one of the leaves.

## How the claims are counted
There are two solutions for counting the claims at relay parent X:
1. Keep a state for the claim queue (number of claims and which of them
are claimed) and look it up when accepting a collation. With this
approach we need to keep the state up to date with each new
advertisement and each new leaf update.
2. Calculate the state of the claim queue on the fly at each
advertisement. This way we rebuild the state of the claim queue at each
advertisements.

Solution 1 is hard to implement with forks. There are too many variants
to keep track of (different state for each leaf) and at the same time we
might never need to use them. So I decided to go with option 2 -
building claim queue state on the fly.

To achieve this I've extended `View` from backing_implicit_view to keep
track of the outer leaves. I've also added a method which accepts a
relay parent and return all paths from an outer leaf to it. Let's call
it `paths_to_relay_parent`.

So how the counting works for relay parent X? First we examine the
number of seconded and pending advertisements (more on pending in a
second) from relay parent X to relay parent X-N (inclusive) where N is
the length of the claim queue. Then we use `paths_to_relay_parent` to
obtain all paths from outer leaves to relay parent X. We calculate the
claims at relay parents X+1 to X+N (inclusive) for each leaf and get the
maximum value. This way we guarantee that the candidate at rp X can be
included in each leaf. This is the state of the claim queue which we use
to decide if we can fetch one more advertisement at rp X or not.

## What is a pending advertisement
I mentioned that we count seconded and pending advertisements at relay
parent X. A pending advertisement is:
1. An advertisement which is being fetched right now.
2. An advertisement pending validation at backing subsystem.
3. An advertisement blocked for seconding by backing because we don't
know on of its parent heads.

Any of these is considered a 'pending fetch' and a slot for it is kept.
All of them are already tracked in `State`.

---------

Co-authored-by: Maciej <maciej.zyszkiewicz@parity.io>
Co-authored-by: command-bot <>
Co-authored-by: Alin Dima <alin@parity.io>

[polkadot-runtime-parachains] migrate paras module to benchmarking v2
syntax

Part of:
* #6202

---------

Co-authored-by: Bastian Köcher <git@kchr.de>

Co-authored-by: GitHub Action <action@github.com>
Co-authored-by: Branislav Kontur <bkontur@gmail.com>
Co-authored-by: command-bot <>

# Description
Issue #6476 
Collation-generation is not needed for validators node, and should be
removed.

## Implementation
Use a `DummySubsystem` for `collation_generation`

---------

Co-authored-by: Bastian Köcher <git@kchr.de>
Co-authored-by: command-bot <>
Co-authored-by: Dmitry Markin <dmitry@markin.tech>
Co-authored-by: Alexandru Vasile <60601340+lexnv@users.noreply.github.com>

`InitiateTransfer`, the new instruction introduced in XCMv5, allows
preserving the origin after a cross-chain transfer via the usage of the
`AliasOrigin` instruction. The receiving chain needs to be configured to
allow such this instruction to have its intended effect and not just
throw an error.

In this PR, I add the alias rules specified in the [RFC for origin
preservation](https://github.com/polkadot-fellows/RFCs/blob/main/text/0122-alias-origin-on-asset-transfers.md)
to westend chains so we can test these scenarios in the testnet.

The new scenarios include:
- Sending a cross-chain transfer from one system chain to another and
doing a Transact on the same message (1 hop)
- Sending a reserve asset transfer from one chain to another going
through asset hub and doing Transact on the same message (2 hops)

The updated chains are:
- Relay: added `AliasChildLocation`
- Collectives: added `AliasChildLocation` and
`AliasOriginRootUsingFilter<AssetHubLocation, Everything>`
- People: added `AliasChildLocation` and
`AliasOriginRootUsingFilter<AssetHubLocation, Everything>`
- Coretime: added `AliasChildLocation` and
`AliasOriginRootUsingFilter<AssetHubLocation, Everything>`

AssetHub already has `AliasChildLocation` and doesn't need the other
config item.
BridgeHub is not intended to be used by end users so I didn't add any
config item.
Only added `AliasChildOrigin` to the relay since we intend for it to be
used less.

---------

Co-authored-by: GitHub Action <action@github.com>
Co-authored-by: command-bot <>

After finality started lagging on kusama around `2025-11-25 15:55:40`
nodes started being overloaded with messages and some restarted with
```
Subsystem approval-distribution-subsystem appears unresponsive when sending a message of type polkadot_node_subsystem_types::messages::ApprovalDistributionMessage. origin=polkadot_service::relay_chain_selection::SelectRelayChainInner<sc_client_db::Backend<sp_runtime::generic::block::Block<sp_runtime::generic::header::Header<u32, sp_runtime::traits::BlakeTwo256>, sp_runtime::OpaqueExtrinsic>>, polkadot_overseer::Handle>
```

I think this happened because our aggression in the current form is way
too spammy and create problems in situation where we already constructed
blocks with a load of candidates to check which what happened around
`#25933682` before and after. However aggression, does help in the
nightmare scenario where the network is segmented and sparsely
connected, so I tend to think we shouldn't completely remove it.

The current configuration is:
```
l1_threshold: Some(16),
l2_threshold: Some(28),
resend_unfinalized_period: Some(8),
```
The way aggression works right now :
1. After L1 is triggered all nodes send all messages they created to all
the other nodes and all messages they would have they already send
according to the topology.
2. Because of resend_unfinalized_period for each block all messages at
step 1) are sent every 8 blocks, so for example let's say we have blocks
1 to 24 unfinalized, then at block 25, all messages for block 1, 9 will
be resent, and consequently at block 26, all messages for block 2, 10
will be resent, this becomes worse as more blocks are created if backing
backpressure did not kick in yet. In total this logic makes that each
node receive 3 * total_number_of messages_per_block
3. L2 aggression is way too spammy, when L2 aggression is enabled all
nodes sends all messages of a block on GridXY, that means that all
messages are received and sent by node at least 2*sqrt(num_validators),
so on kusama would be 66 * NUM_MESSAGES_AT_FIRST_UNFINALIZED_BLOCK, so
even with a reasonable number of messages like 10K, which you can have
if you escalated because of no shows, you end-up sending and receiving
~660k messages at once, I think that's what makes the
approval-distribution to appear unresponsive on some nodes.
4. Duplicate messages are received by the nodes which turn, mark the
node as banned, which may create more no-shows.

## Proposed improvements:
1. Make L2 trigger way later 28 blocks, instead of 64, this should
literally the last resort, until then we should try to let the
approval-voting escalation mechanism to do its things and cover the
no-shows.
2. On L1 aggression don't send messages for blocks too far from the
first_unfinalized there is no point in sending the messages for block
20, if block 1 is still unfinalized.
3. On L1 aggression, send messages then back-off for 3 *
resend_unfinalized_period to give time for everyone to clear up their
queues.
4. If aggression is enabled accept duplicate messages from validators
and don't punish them by reducting their reputation which, which may
create no-shows.

---------

Signed-off-by: Alexandru Gheorghe <alexandru.gheorghe@parity.io>
Co-authored-by: Andrei Sandu <54316454+sandreim@users.noreply.github.com>

# Description
Migrated polkadot-runtime-common auctions benchmarking to the new
benchmarking syntax v2.
This is part of #6202

---------

Co-authored-by: Giuseppe Re <giuseppe.re@parity.io>
Co-authored-by: Bastian Köcher <git@kchr.de>

## Description

Our smoke tests transfer `WETH` from Sepolia to Westend-AssetHub breaks,
try to reregister `WETH` on AH but fails as following:


https://bridgehub-westend.subscan.io/xcm_message/westend-4796d6b3600aca32ef63b9953acf6a456cfd2fbe

https://assethub-westend.subscan.io/extrinsic/9731267-0?event=9731267-2

The reason is that the transact call encoded on BH to register the asset

https://github.com/paritytech/polkadot-sdk/blob/a77940ba

/bridges/snowbridge/primitives/router/src/inbound/mod.rs#L282-L289
```
0x3500020209079edaa8020300fff9976782d46cc05630d1f6ebab18b2324d6b1400ce796ae65569a670d0c1cc1ac12515a3ce21b5fbf729d63d7b289baad070139d01000000000000000000000000000000
```

the `asset_id` which is the xcm location can't be decoded on AH in V5

Issue initial post in
https://matrix.to/#/!qUtSTcfMJzBdPmpFKa:parity.io/$RNMAxIIOKGtBAqkgwiFuQf4eNaYpmOK-Pfw4d6vv1aU?via=parity.io&via=matrix.org&via=web3.foundation

---------

Co-authored-by: Adrian Catangiu <adrian@parity.io>
Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com>

The way we build the messages we need to send to approval-distribution
can result in a situation where is we have multiple assignments covered
by a coalesced approval, the messages are sent in this order:

ASSIGNMENT1, APPROVAL, ASSIGNMENT2, because we iterate over each
candidate and add to the queue of messages both the assignment and the
approval for that candidate, and when the approval reaches the
approval-distribution subsystem it won't be imported and gossiped
because one of the assignment for it is not known.

So in a network where a lot of nodes are restarting at the same time we
could end up in a situation where a set of the nodes correctly received
the assignments and approvals before the restart and approve their
blocks and don't trigger their assignments. The other set of nodes
should receive the assignments and approvals after the restart, but
because the approvals never get broacasted anymore because of this bug,
the only way they could approve is if other nodes start broadcasting
their assignments.

I think this bug contribute to the reason the network did not recovered
on `25-11-25 15:55:40` after the restarts.

Tested this scenario with a `zombienet` where `nodes` are finalising
blocks because of aggression and all nodes are restarted at once and
confirmed the network lags and doesn't recover before and it does after
the fix

---------

Signed-off-by: Alexandru Gheorghe <alexandru.gheorghe@parity.io>

Close: #5858

---------

Co-authored-by: Bastian Köcher <git@kchr.de>

Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com>

# Description

Sending XCM messages to other chains requires paying a "transport fee".
This can be paid either:
- from `origin` local account if `jit_withdraw = true`,
- taken from Holding register otherwise.

This currently works for following hops/scenarios:
1. On destination no transport fee needed (only sending costs, not
receiving),
2. Local/originating chain: just set JIT=true and fee will be paid from
signed account,
3. Intermediary hops - only if intermediary is acting as reserve between
two untrusted chains (aka only for `DepositReserveAsset` instruction) -
this was fixed in https://github.com/paritytech/polkadot-sdk/pull/3142

But now we're seeing more complex asset transfers that are mixing
reserve transfers with teleports depending on the involved chains.

# Example

E.g. transferring DOT between Relay and parachain, but through AH (using
AH instead of the Relay chain as parachain's DOT reserve).

In the `Parachain --1--> AssetHub --2--> Relay` scenario, DOT has to be
reserve-withdrawn in leg `1`, then teleported in leg `2`.
On the intermediary hop (AssetHub), `InitiateTeleport` fails to send
onward message because of missing transport fees. We also can't rely on
`jit_withdraw` because the original origin is lost on the way, and even
if it weren't we can't rely on the user having funded accounts on each
hop along the way.

# Solution/Changes

- Charge the transport fee in the executor from the transferred assets
(if available),
- Only charge from transferred assets if JIT_WITHDRAW was not set,
- Only charge from transferred assets if unless using XCMv5 `PayFees`
where we do not have this problem.

# Testing

Added regression tests in emulated transfers.

Fixes https://github.com/paritytech/polkadot-sdk/issues/4832
Fixes https://github.com/paritytech/polkadot-sdk/issues/6637

---------

Signed-off-by: Adrian Catangiu <adrian@parity.io>
Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com>

After finality started lagging on kusama around 025-11-25 15:55:40
validators started seeing ocassionally this log, when importing votes
covering more than one assignment.
```
Possible bug: Vote import failed
```

That happens because the assumption that assignments from the same
validator would have the same required routing doesn't hold after you
enabled aggression, so you might end up receiving the first assignment
then you modify the routing for it in `enable_aggression` then your
receive the second assignment and the vote covering both assignments, so
the rouing for the first and second assingment wouldn't match and we
would fail to import the vote.

From the logs I've seen, I don't think this is the reason the network
didn't fully recover until the failsafe kicked it, because the votes had
been already imported in approval-voting before this error.

---------

Signed-off-by: Alexandru Gheorghe <alexandru.gheorghe@parity.io>

- change bench to default to old CLI
- fix profile to production

---------

Co-authored-by: GitHub Action <action@github.com>
Co-authored-by: command-bot <>

Last feature we wanted for V5, changing `SetAssetClaimer` to be just one
of many possible "hints" that you can specify at the beginning of your
program to change its behaviour.

This makes it easier to add new hints in the future and have barriers
accept them.

---------

Co-authored-by: GitHub Action <action@github.com>

Co-authored-by: command-bot <>

Closes: https://github.com/paritytech/polkadot-sdk/issues/6585

Removing the `require_weight_at_most` parameter in V5 Transact had only
one problem. Converting a message from V5 to V4 to send to chains that
didn't upgrade yet. The conversion would not know what weight to give to
the Transact, since V4 and below require it.

To fix this, I added back the weight in the form of an `Option<Weight>`
called `fallback_max_weight`. This can be set to `None` if you don't
intend to deal with a chain that hasn't upgraded yet. If you set it to
`Some(_)`, the behaviour is the same. The plan is to totally remove this
in V6 since there will be a good conversion path from V6 to V5.

---------

Co-authored-by: GitHub Action <action@github.com>
Co-authored-by: Adrian Catangiu <adrian@parity.io>

This might actually happen in non malicious cases.

Co-authored-by: eskimor <eskimor@no-such-url.com>

# Description
Migrated pallet-xcm-benchmarks to benchmaking syntax V2
This is part of #6202

---------

Co-authored-by: Giuseppe Re <giuseppe.re@parity.io>

The `query_weight_to_asset_fee` function was trying to convert versions
by using `try_as`, this function [doesn't convert from a versioned to a
concrete
type](https://github.com/paritytech/polkadot-sdk/blob/0156ca8f/polkadot/xcm/src/lib.rs#L131).
This would cause all calls with a lower version to fail.

The correct function to use is the good old
[try_into](https://github.com/paritytech/polkadot-sdk/blob/0156ca8f

/polkadot/xcm/src/lib.rs#L184).
Now those calls work :)

---------

Co-authored-by: command-bot <>
Co-authored-by: Branislav Kontur <bkontur@gmail.com>
Co-authored-by: GitHub Action <action@github.com>

This PR addresses two small fixes:  

1. Fixed a typo ("as as") found on the way.  
2. Resolved a bug in the `local/remote exporters` used for bridging.
Previously, they consumed `dest` and `msg` without returning them when
inner routers/exporters failed with `NotApplicable`. This PR ensures
compliance with the
[`SendXcm`](https://github.com/paritytech/polkadot-sdk/blob/master/polkadot/xcm/src/v5/traits.rs#L449-L450)
and
[`ExportXcm`](https://github.com/paritytech/polkadot-sdk/blob/master/polkadot/xcm/xcm-executor/src/traits/export.rs#L44-L45)
traits.

---------

Co-authored-by: GitHub Action <action@github.com>

Closes #6415 

# Description

Remove unused message `ReportCollator` and test related to this message
on the collator protocol validator side.

cc: @tdimitrov



---------

Co-authored-by: Tsvetomir Dimitrov <tsvetomir@parity.io>
Co-authored-by: command-bot <>

Co-authored-by: Robert <robert@gonimo.com>
Co-authored-by: ordian <write@reusable.software>

Step in https://github.com/paritytech/polkadot-sdk/issues/3268

This PR adds the ability for these pallets to specify their source of
the block number. This is useful when these pallets are migrated from
the relay chain to a parachain and vice versa.

This change is backwards compatible:
1. If the `BlockNumberProvider` continues to use the system pallet's
block number
2. When a pallet deployed on the relay chain is moved to a parachain,
but still uses the relay chain's block number

However, we would need migrations if the deployed pallets are upgraded
on an existing parachain, and the `BlockNumberProvider` uses the relay
chain block number.

---------

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

This pull request forward all the logging directives given to the node
via `RUST_LOG` or `-l` to the workers, instead of only forwarding
`RUST_LOG`.

---------

Co-authored-by: GitHub Action <action@github.com>

Aims to implement Stage 3 of Validator Disbling as outlined here:
https://github.com/paritytech/polkadot-sdk/issues/4359

Features:
- [x] New Disabling Strategy (Staking level)
- [x] Re-enabling logic (Session level)
- [x] More generic disabling decision output
- [x] New Disabling Events

Testing & Security:
- [x] Unit tests
- [x] Mock tests
- [x] Try-runtime checks
- [x] Try-runtime tested on westend snap
- [x] Try-runtime CI tests
- [ ] Re-enabling Zombienet Test (?)
- [ ] SRLabs Audit

Closes #4745 
Closes #2418

---------

Co-authored-by: ordian <write@reusable.software>
Co-authored-by: Ankan <10196091+Ank4n@users.noreply.github.com>
Co-authored-by: Tsvetomir Dimitrov <tsvetomir@parity.io>

Since async backing parameters runtime api is released on all networks
the code in backing subsystem can be simplified by removing the usages
of `ProspectiveParachainsMode` and keeping only the branches of the code
under `ProspectiveParachainsMode::Enabled`.

The PR does that and reworks the tests in mod.rs to use async backing.
It's a preparation for
https://github.com/paritytech/polkadot-sdk/issues/5079

---------

Co-authored-by: Alin Dima <alin@parity.io>
Co-authored-by: command-bot <>