cibuildwheel 2.x no longer supports Python < 3.6. Please use the 1.x series or update CIBW_SKIP

While cibuildwheel can build CPython 3.8 universal2/arm64 wheels, we cannot test the arm64 part of them, even when running on an Apple Silicon machine. This is because we use the x86_64 installer of CPython 3.8. See the discussion in https://github.com/pypa/cibuildwheel/pull/1169 for the details. To silence this warning, set `CIBW_TEST_SKIP: "cp38-macosx_*:arm64"`.

The following actions use a deprecated Node.js version and will be forced to run on node20: actions/checkout@v3, actions/setup-python@v3. For more info: https://github.blog/changelog/2024-03-07-github-actions-all-actions-will-run-on-node20-instead-of-node16-by-default/