Add Python 3.11 and PyPy 3.9 to the testing and drop 3.6

[cclauss]

• https://github.com/actions/cache/releases
• https://github.com/actions/checkout/releases
• https://github.com/actions/setup-python/releases
• https://docs.python.org/3/whatsnew/3.11.html
• https://www.pypy.org/download.html

[cclauss]

@RonnyPfannschmidt @ssbarnea Can you please approve the workflow run so we can see if it passes?

[ssbarnea]

Is not a problem of approval, there is no option. Changes made to a workflow must come from another branch in the repository in order to be tested correctly by GHA. When they come from a pull-request, they are not applied as someone would expect.

[hugovk]

@cclauss The CI is failing.

[hugovk]

https://github.com/pytest-dev/pytest-cov/actions/runs/4215078717/jobs/7315964982 is erroring because GitHub Actions is dropping support for EOL Python 3.6.

pytest itself dropped 3.6 in 2021: https://github.com/pytest-dev/pytest/issues/9437

[Mason-Lin]

Need to update pytest-xdist >=3.1.0 #842: Python 3.11 is now officially supported.

https://pytest-xdist.readthedocs.io/en/latest/changelog.html#pytest-xdist-3-1-0-2022-12-01

[Pierre-Sassoulas]

@Mason-Lin There's no need to update pytest-xdist, pip will take the version compatible with the user interpreter (provided metadata are correct in pytest-xdist packaging). We might make the resolution impossible for lower interpreter version if we do that (i.e. no compatible pytest-xdist for python 3.7 or a false incompatibility with another dependencie that need an old pytest-xdist)

[cclauss]

@hugovk @Mason-Lin @Pierre-Sassoulas Your reviews, please.

[Mason-Lin]

@Mason-Lin There's no need to update pytest-xdist, pip will take the version compatible with the user interpreter (provided metadata are correct in pytest-xdist packaging). We might make the resolution impossible for lower interpreter version if we do that (i.e. no compatible pytest-xdist for python 3.7 or a false incompatibility with another dependencie that need an old pytest-xdist)

I originally saw pytest-xdist==3.0.2 in tox.ini. After checking the changelog, it seems that only 3.2.0 supports python 3.11. I thought it was just a typo, I am not very familiar with this project.😅 The following commit done much more, such as skip boxed option. Sorry for giving a wrong direction with a positive tone, I was really just guessing, thanks for the detailed explanation.

[cclauss]

The pypy team dropped pypy3.7 https://www.pypy.org/download.html