chore: bump pytest version and include pytest-xdist

[henryiii]

Minor cleanup. Require pytest 7.2+.

[LecrisUT]

Does embedding -n auto in the pyproject.toml work? Might as well add it to the fedora ci as well

[henryiii]

We could, but then it would be opt-out instead of opt-in. I think pytest test/file.py::test_case will not trigger the threads if we don't inject -n auto, but would if we do. Could be wrong, though.