Bump hex-literal from 0.2.1 to 0.3.4 (#1028)

Bumps [hex-literal](https://github.com/RustCrypto/utils) from 0.2.1 to 0.3.4.
- [Release notes](https://github.com/RustCrypto/utils/releases)
- [Commits](https://github.com/RustCrypto/utils/compare/hex-literal-v0.2.1...hex-literal-v0.3.4)

---
updated-dependencies:
- dependency-name: hex-literal
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

cumulus/polkadot-parachains/Cargo.toml

@@ -15,7 +15,7 @@ futures = { version = "0.3.1", features = ["compat"] }
 log = "0.4.8"
 codec = { package = "parity-scale-codec", version = "2.3.0" }
 serde = { version = "1.0.132", features = ["derive"] }
-hex-literal = "0.2.1"
+hex-literal = "0.3.4"
 async-trait = "0.1.42"
 
 # Parachain runtimes