Update async-channel requirement from 1.4.2 to 2.0.0

Updates the requirements on [async-channel](https://github.com/smol-rs/async-channel) to permit the latest version.
- [Release notes](https://github.com/smol-rs/async-channel/releases)
- [Changelog](https://github.com/smol-rs/async-channel/blob/master/CHANGELOG.md)
- [Commits](smol-rs/async-channel@v1.4.2...v2.0.0)

---
updated-dependencies:
- dependency-name: async-channel
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.toml

@@ -15,7 +15,7 @@ categories = ["asynchronous", "concurrency", "network-programming"]
 exclude = ["/.*"]
 
 [dependencies]
-async-channel = "1.4.2"
+async-channel = "2.0.0"
 async-executor = "1.5.0"
 async-fs = "1.3.0"
 async-io = "1.12.0"