Update async-lock requirement from 2.6 to 3.0

Updates the requirements on [async-lock](https://github.com/smol-rs/async-lock) to permit the latest version.
- [Release notes](https://github.com/smol-rs/async-lock/releases)
- [Changelog](https://github.com/smol-rs/async-lock/blob/master/CHANGELOG.md)
- [Commits](smol-rs/async-lock@v2.6.0...v3.0.0)

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

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

Cargo.toml

@@ -23,7 +23,7 @@ name = "timer"
 harness = false
 
 [dependencies]
-async-lock = "2.6"
+async-lock = "3.0"
 cfg-if = "1"
 concurrent-queue = "2.2.0"
 futures-io = { version = "0.3.28", default-features = false, features = ["std"] }