title: "Bridge: make some headers submissions free"

doc:
  - audience: Runtime Dev
    description: |
      Adds `FreeHeadersInterval` configuration constant to the `pallet_bridge_grandpa`.
      Transactions that improve best known header by at least `FreeHeadersInterval` headers
      are now free for the submitter. Additionally, we allow single free parachain header
      update per every free relay chain header. Bridge signed extensions are adjusted
      to support that new scheme. Bridge runtime APIs are extended to support that new
      scheme. Bridge fees are decreased by ~98% because now they do not include cost of
      finality submissions - we assume relayers will be submitting finality transactions
      for free.

crates:
  - name: bridge-runtime-common
    bump: major
  - name: bp-bridge-hub-cumulus
    bump: patch
  - name: bp-bridge-hub-kusama
    bump: major
  - name: bp-bridge-hub-polkadot
    bump: major
  - name: bp-bridge-hub-rococo
    bump: major
  - name: bp-bridge-hub-westend
    bump: major
  - name: pallet-bridge-grandpa
    bump: major
  - name: pallet-bridge-parachains
    bump: major
  - name: bp-parachains
    bump: major
  - name: bp-runtime
    bump: major
  - name: relay-substrate-client
    bump: major
  - name: bridge-hub-rococo-runtime
    bump: major
  - name: bridge-hub-westend-runtime
    bump: major
  - name: bridge-hub-test-utils
    bump: minor