HotfixStatusChecker: improvements

- Use `gitpython` instead of executing things like `cd ... && git ...` using a shell and parsing the result.
- Use the normal python logging infrastructure instead of `print("DEBUG: ...")`
- Migrate to a standard `pyproject.toml` setup

Locate HotfixStatusChecker and inspect its current shell-based Git calls, print-based debug output, and packaging setup. Check how GitPython, Python logging, and pyproject.toml would fit the existing structure; done means all three requested migrations are complete without shell parsing or direct debug prints.

Scritto dal modello di indicizzazione a partire dal testo della issue.