Bump music21-rs in the rust-dependencies group

Bumps the rust-dependencies group with 1 update: [music21-rs](https://github.com/float3/music21-rs).


Updates `music21-rs` from `4ed32c5` to `422716a`
- [Release notes](https://github.com/float3/music21-rs/releases)
- [Commits](float3/music21-rs@4ed32c5...422716a)

---
updated-dependencies:
- dependency-name: music21-rs
  dependency-version: 422716acfefcfb78d0712e21ae4c7bc361d3dcad
  dependency-type: direct:production
  dependency-group: rust-dependencies
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]