Use pathlib.Path in plugin hooks

[michael-k]

Fixes compatibility with pytest 8.1, see

• hookspec: add pathlib.Path alternatives to py.path.local parameters in hooks pytest-dev/pytest#8144
• https://docs.pytest.org/en/stable/changelog.html#id282
• https://docs.pytest.org/en/stable/deprecations.html#py-path-local-arguments-for-hooks-replaced-with-pathlib-path

Fixes #192

[michael-k]

pytest 8.1 was yanked. But not because they want to revert the changes, but because the warnings did not appear properly. See pytest-dev/pytest#12069

[mr-c]

pytest 8.1 was yanked. But not because they want to revert the changes, but because the warnings did not appear properly. See pytest-dev/pytest#12069

👍 These changes are compatible with pytest 7.x+

[michael-k]

Yes, my PR is compatible with both pytest 7.0.x and the yanked 8.1.0. I ran the tests in my fork and everything was green.