Update async-net requirement from 1.4.3 to 2.0.0

Updates the requirements on [async-net](https://github.com/smol-rs/async-net) to permit the latest version.
- [Release notes](https://github.com/smol-rs/async-net/releases)
- [Changelog](https://github.com/smol-rs/async-net/blob/master/CHANGELOG.md)
- [Commits](smol-rs/async-net@v1.4.3...v2.0.0)

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

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

Cargo.toml

@@ -20,7 +20,7 @@ async-executor = "1.5.0"
 async-fs = "1.3.0"
 async-io = "1.12.0"
 async-lock = "2.6.0"
-async-net = "1.4.3"
+async-net = "2.0.0"
 blocking = "1.3.0"
 futures-lite = "1.11.0"