chore(deps): bump clap from 4.5.20 to 4.5.21

Bumps [clap](https://github.com/clap-rs/clap) from 4.5.20 to 4.5.21.
- [Release notes](https://github.com/clap-rs/clap/releases)
- [Changelog](https://github.com/clap-rs/clap/blob/master/CHANGELOG.md)
- [Commits](clap-rs/clap@clap_complete-v4.5.20...clap_complete-v4.5.21)

---
updated-dependencies:
- dependency-name: clap
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Cargo.toml

@@ -17,7 +17,7 @@ name = "collatz"
 path = "src/main.rs"
 
 [dependencies]
-clap = { version = "4.5.20", features = ["derive", "env", "cargo", "help"] }
+clap = { version = "4.5.21", features = ["derive", "env", "cargo", "help"] }
 clap_complete = "4.5.37"
 libc = "0.2.162"
 num = { version = "0.4.3", features = ["num-bigint"] }