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"`.

Setting SYSTEM_VERSION_COMPAT=0 to ensure CPython 3.8 can get correct macOS version and allow installation of wheels with MACOSX_DEPLOYMENT_TARGET >= 11.0. See https://github.com/pypa/cibuildwheel/issues/1767 for the details.