Support pytest 8 changes.

[s-t-e-v-e-n-k]

Closes #499

pytest 8 removed the hook that was calling nose-specific methods, such as setup and teardown. However, there is still support for that, the methods just have _method on the end, so change them both.

[mulkieran]

Thanks. I think there are a couple more like that that need fixing. Could you edit https://github.com/pyudev/pyudev/blob/master/.github/workflows/main.yml so that it no longer explicitly requires pytest version 7 as well?

[s-t-e-v-e-n-k]

tests/test_observer_deprecated.py is fine, it has setup and teardown, but they are called from setup_method and teardown_method, so that doesn't need changing.

[mulkieran]

@s-t-e-v-e-n-k Ok, thx, merging.