Bump parking_lot from 0.12.0 to 0.12.1 (#1322)

Bumps [parking_lot](https://github.com/Amanieu/parking_lot) from 0.12.0 to 0.12.1.
- [Release notes](https://github.com/Amanieu/parking_lot/releases)
- [Changelog](https://github.com/Amanieu/parking_lot/blob/master/CHANGELOG.md)
- [Commits](https://github.com/Amanieu/parking_lot/compare/0.12.0...0.12.1)

---
updated-dependencies:
- dependency-name: parking_lot
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

cumulus/client/relay-chain-rpc-interface/Cargo.toml

@@ -22,7 +22,7 @@ sc-rpc-api = { git = "https://github.com/paritytech/substrate", branch = "master
 futures = "0.3.21"
 futures-timer = "3.0.2"
 parity-scale-codec = "3.1.2"
-parking_lot = "0.12.0"
+parking_lot = "0.12.1"
 jsonrpsee = { version = "0.13.1", features = ["ws-client"] }
 tracing = "0.1.34"
 async-trait = "0.1.53"