fix: catch KeyError when accessing __name__ in _idval_from_value (#14560)

[NIK-TIGER-BILL]

Description

Fixes #14560.

Custom classes with a __getattr__ that raises KeyError (instead of AttributeError) would crash pytest during parameterized test id generation. This PR catches both AttributeError and KeyError when trying to access __name__.

Checklist

• Include new tests or update existing tests when applicable.
• Allow maintainers to push and squash when merging my commits.
• Add text like closes #14560 to the PR description and/or commits.
• Create a new changelog file in the changelog directory.
• Add yourself to AUTHORS in alphabetical order.

[RonnyPfannschmidt]

Nope it's valid to fail there

[NIK-TIGER-BILL]

Thanks for the quick feedback! I see your point—raising KeyError inside __getattr__ violates the Python data-model protocol (__getattr__ should raise AttributeError). However, the issue reporter (#14560) hit this with a third-party wrapper class they don’t control. Would you prefer that pytest stay strict and leave the crash as-is, or should we catch the exception and treat it as ‘no __name__’ so that test-id generation never crashes on broken __getattr__ implementations? Happy to adjust or close if the consensus is ‘wont-fix’.