Companion for Polkadot#7337 (#2929)

* Companion for Polkadot#7337

Companion for paritytech/polkadot#7337

* Remove unnecessary items relating to PVF workers

* Remove `dont_use_external_workers` parameter

* Update Cargo.lock

* update lockfile for {"polkadot", "substrate"}

* Update Cargo.lock

* update lockfile for {"polkadot", "substrate"}

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Co-authored-by: parity-processbot <>