chore: [torrust#639] add cargo dependency: hex_literal

It allows simplifying the wasy we build InfoHashes from hex strings:

```rust
let info_hash = InfoHash(hex!("9c38422213e30bff212b30c360d26f9a02136422")); // # DevSkim: ignore DS173237
```

Author: josecelano

Cargo.lock

@@ -74,6 +74,7 @@ url = "2.5.0"
 tempfile = "3.9.0"
 clap = { version = "4.4.18", features = ["derive", "env"]}
 anyhow = "1.0.79"
+hex-literal = "0.4.1"
 
 [dev-dependencies]
 criterion = { version = "0.5.1", features = ["async_tokio"] }