build(deps): update hex requirement from =0.4.0 to =0.4.2

Updates the requirements on [hex](https://github.com/KokaKiwi/rust-hex) to permit the latest version.
- [Release notes](https://github.com/KokaKiwi/rust-hex/releases)
- [Commits](KokaKiwi/rust-hex@v0.4...v0.4.2)

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

heim-net/Cargo.toml

@@ -34,7 +34,7 @@ version-sync = "0.8"
 nix = "0.17.0"
 
 [target.'cfg(target_os = "linux")'.dependencies]
-hex = "=0.4.0"
+hex = "=0.4.2"
 
 [features]
 # Polyfill runtime is enabled by default only to execute examples, tests and benchmarks.