chore: remove unused dependencies detected by cargo-machete

Remove unused dependencies from both main and linting packages:
- Main package: removed 'dirs' and 'serde' dependencies
- Linting package: removed 'regex' dependency

This fixes the cargo-machete CI check that was failing in the testing workflow.

Author: josecelano

Cargo.toml

@@ -26,11 +26,9 @@ path = "src/bin/linter.rs"
 
 [dependencies]
 tokio = { version = "1.0", features = [ "full" ] }
-serde = { version = "1.0", features = [ "derive" ] }
 serde_json = "1.0"
 anyhow = "1.0"
 clap = { version = "4.0", features = [ "derive" ] }
 regex = "1.0"
-dirs = "5.0"
 tempfile = "3.0"
 torrust-linting = { path = "packages/linting" }

packages/linting/Cargo.toml

@@ -11,7 +11,6 @@ path = "src/lib.rs"
 
 [dependencies]
 anyhow = "1.0"
-regex = "1.0"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = [ "env-filter" ] }
 clap = { version = "4.0", features = [ "derive" ] }