Ignore annotated lambdas in class scopes

[charliermarsh]

Summary

An annotated lambda assignment within a class scope is often intentional. For example, within a dataclass or Pydantic model, these are treated as fields rather than methods (and so can be passed values in constructors).

I originally wrote this to special-case dataclasses and Pydantic models... But was left feeling like we'd see more false positives here for little gain (an annotated lambda within a class is likely intentional?). Open to opinions, though.

Closes #10718.

[github-actions]

ruff-ecosystem results

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[AlexWaygood]

What a weird edge case. This makes sense to me!