Bump crossbeam-channel from 0.4.2 to 0.4.4

Bumps [crossbeam-channel](https://github.com/crossbeam-rs/crossbeam) from 0.4.2 to 0.4.4.
- [Release notes](https://github.com/crossbeam-rs/crossbeam/releases)
- [Changelog](https://github.com/crossbeam-rs/crossbeam/blob/master/CHANGELOG.md)
- [Commits](crossbeam-rs/crossbeam@v0.4.2...crossbeam-channel-0.4.4)

---
updated-dependencies:
- dependency-name: crossbeam-channel
  dependency-type: indirect
...

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