Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/setup-python@v5, actions/upload-artifact@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

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"`.