Update hex-literal requirement from 0.3 to 0.4

Updates the requirements on [hex-literal](https://github.com/RustCrypto/utils) to permit the latest version.
- [Release notes](https://github.com/RustCrypto/utils/releases)
- [Commits](RustCrypto/utils@hex-literal-v0.3.0...hex-literal-v0.4.1)

---
updated-dependencies:
- dependency-name: hex-literal
  dependency-type: direct:production
...

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

Cargo.toml

@@ -59,7 +59,7 @@ wasm-bindgen-futures = { version = "0.4.18", optional = true }
 [dev-dependencies]
 # For examples
 env_logger = "0.10"
-hex-literal = "0.3"
+hex-literal = "0.4"
 wasm-bindgen-test = "0.3.19"
 
 [target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]