TST: Replace ensure_clean_store with tmp_path in test_complex.py, test_file_handling.py

[micol-altomare]

• Contributes to TST: Replace ensure_clean utility function with the temp_file pytest fixture #62435

Replace ensure_clean_store with tmp_path fixture in the following files:

• pandas/tests/io/pytables/test_keys.py
• pandas/tests/io/pytables/test_complex.py
• pandas/tests/io/pytables/test_file_handling.py

Specifically,

• Replace all occurrences of ensure_clean_store with + HDFStore(tmp_path / setup_path)
• Removed ensure_clean_store imports (no longer used)
• Added tmp_path parameter to modified test functions

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• Code fixes #xxx
• Tests added and passed if fixing a bug or adding a new feature
• All code checks passed.
• Added type annotations to new arguments/methods/functions.
• Added an entry in the latest doc/source/whatsnew/vX.X.X.rst file if fixing a bug or adding a new feature.
• If I used AI to develop this pull request, I prompted it to follow AGENTS.md.

[micol-altomare]

Hi @mroeschke! 👋 Would you mind reviewing this PR (for #62435) and letting me know if there are any changes needed on my end in order to successfully merge? Thank you in advance!