Use pytest tmp file management fixtures instead of ensure_clean[_path|_dir]
Opened as of discussion in https://github.com/pandas-dev/pandas/pull/26818.

`tests/io/test_pytables.py` uses a context manager called `ensure_clean_path`. It might be worth using the pytest `tmp_path` fixture instead which I think provides everything we need with less code (also easier to understand for new contributors familiar with pytest). And it provides even a little more functionality, comparison:
- it guarantees file system isolation between tests (as does `ensure_clean_path`).
- it makes it obvious which file belongs to which test via expressive naming (as opposed to `ensure_clean_path`).
- it retains files for later inspection as opposed to `ensure_clean_path`. That can be useful for debugging after test failure.

Note: the pytest-managed temp files are removed in a rolling fashion across test runner invocations so that storage space requirement does not grow indefinitely with the number of invocations.

Cf. comment https://github.com/pandas-dev/pandas/pull/26818#issuecomment-504368606