* Limit the number of PVF workers

In particular, limit the number of preparation workers to 1 (soft &
hard) and limit the number of execution workers to 2.

The reason why we are doing this is that it seems many workers launched
at the same time can cause problems. I.e. if there are more than 2
preparation workers, the time for preparation rises significantly to the
point of reaching the timeout.

This was mostly observed with parallel_compilation=true, so each worker
used `numcpu` threads and now we are looking to flip that parameter to
`false`. That said, we want to err on the safe side here and gradually
enable it later if our measurements show that we can do that safely.

* Adjust the test to accomodate the changed config value

* pvf: make execution timeout configurable

* guide: add timeouts to candidate validation params

* add timeouts to candidate validation messages

* fmt

* port backing to use the backing pvf timeout

* port approval-voting to use the execution timeout

* port dispute participation to use the correct timeout

* fmt

* address grumbles & test failure

* cargo +nightly fmt

* add cargo-fmt check to ci

* update ci

* fmt

* fmt

* skip macro

* ignore bridges

* Use wasm-builder from git

This brings new features like compressed runtimes out of the box.

* chore: update wasm builder dep. from 3.0.0 to master

* Fix tests

* Update node/core/pvf/tests/it/main.rs

Co-authored-by: Sergei Shulepov <[email protected]>

Co-authored-by: chevdor <[email protected]>
Co-authored-by: Sergei Shulepov <[email protected]>

* Implement PVF validation host

* WIP: Diener

* Increase the alloted compilation time

* Add more comments

* Minor clean up

* Apply suggestions from code review

Co-authored-by: Bastian Köcher <[email protected]>

* Fix pruning artifact removal

* Fix formatting and newlines

* Fix the thread pool

* Update node/core/pvf/src/executor_intf.rs

Co-authored-by: Bastian Köcher <[email protected]>

* Remove redundant test declaration

* Don't convert the path into an intermediate string

* Try to workaround the test failure

* Use the puppet_worker trick again

* Fix a blip

* Move `ensure_wasmtime_version` under the tests mod

* Add a macro for puppet_workers

* fix build for not real-overseer

* Rename the puppet worker for adder collator

* play it safe with the name of adder puppet worker

* Typo: triggered

* Add more comments

* Do not kill exec worker on every error

* Plumb Duration for timeouts

* typo: critical

* Add proofs

* Clean unused imports

* Revert "WIP: Diener"

This reverts commit b9f54e513366c7a6dfdd117ac19fbdc46b900b4d.

* Sync version of wasmtime

* Update cargo.lock

* Update Substrate

* Merge fixes still

* Update wasmtime version in test

* bastifmt

Co-authored-by: Bastian Köcher <[email protected]>

* Squash spaces

* Trailing new line for testing.rs

* Remove controversial code

* comment about biasing

* Fix suggestion

* Add comments

* make it more clear why unwrap_err

* tmpfile retry

* proper proofs for claim_idle

* Remove mutex from ValidationHost

* Add some more logging

* Extract exec timeout into a constant

* Add some clarifying logging

* Use blake2_256

* Clean up the merge

Specifically the leftovers after removing real-overseer

* Update parachain/test-parachains/adder/collator/Cargo.toml

Co-authored-by: Andronik Ordian <[email protected]>

Co-authored-by: Bastian Köcher <[email protected]>
Co-authored-by: Andronik Ordian <[email protected]>