Bump the rust-dependencies group with 2 updates

Bumps the rust-dependencies group with 2 updates: [rodio](https://github.com/RustAudio/rodio) and [serial_test](https://github.com/palfrey/serial_test).


Updates `rodio` from 0.21.1 to 0.22.1
- [Changelog](https://github.com/RustAudio/rodio/blob/master/CHANGELOG.md)
- [Commits](RustAudio/rodio@v0.21.1...v0.22.1)

Updates `serial_test` from 3.3.1 to 3.4.0
- [Release notes](https://github.com/palfrey/serial_test/releases)
- [Commits](palfrey/serial_test@v3.3.1...v3.4.0)

---
updated-dependencies:
- dependency-name: rodio
  dependency-version: 0.22.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: rust-dependencies
- dependency-name: serial_test
  dependency-version: 3.4.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: rust-dependencies
...

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Author: dependabot[bot]