TST: Replace ensure_clean_store with tmp_path in test_timezones.py

[Chiwendaiyue]

Replace ensure_clean_store with tmp_path in test_timezones.py

What does this PR do?
This PR migrates the test file pandas/tests/io/pytables/test_timezones.py from using the custom ensure_clean_store utility to the standard pytest tmp_path fixture.
Why is this change needed?
As part of the ongoing effort to modernize the pandas test suite, we're replacing the custom ensure_clean utility function with pytest's built-in tmp_path fixture. This:

• Reduces code duplication
• Uses standard pytest functionality
• Makes tests more consistent across the codebase
• Follows pytest best practices
  What changes were made?
• Replaced with ensure_clean_store(setup_path) as store: with path = tmp_path / "filename.h5" and with pd.HDFStore(path) as store:
• Used unique filenames for each test to prevent conflicts
• Removed the import of ensure_clean_store
• Maintained all existing test logic and functionality

Testing

• All existing tests pass (71 passed, 1 skipped)
• No behavioral changes to the tests
• Manual verification of test functionality
  Related Issues
  Part of the larger effort to replace ~180 occurrences of ensure_clean throughout the codebase.Fixes TST: Replace ensure_clean utility function with the temp_file pytest fixture #62435

[mroeschke]

Thanks @Chiwendaiyue