## Summary
While I was here, I also updated the rule to use
`function_type::classify` rather than hard-coding `staticmethod` and
friends.
Per Carl:
> Enum instances are already referred to by the class, forming a cycle
that won't get collected until the class itself does. At which point the
`lru_cache` itself would be collected, too.
Closes https://github.com/astral-sh/ruff/issues/9912.