ruff

ff7086d9 - [ty] Infer type of implicit `cls` parameter in method bodies (#21685)

[ty] Infer type of implicit `cls` parameter in method bodies (#21685) ## Summary Extends https://github.com/astral-sh/ruff/pull/20922 to infer unannotated `cls` parameters as `type[Self]` in method bodies. Part of https://github.com/astral-sh/ty/issues/159.