Pypy wheel macos - build on macOS 10.15

[Spitfire1900]

Per cibuildwheel's documentation PyPy 3.9+ support is only available on macOS 10.15.

I don't know if this breaks compatibility with runtimes on 10.14, 10.15 though 🙁

[Spitfire1900]

The following error is thrown when attempting to build the wheel, I'm not familiar enough to know if this is because of in issue in PyGit2's build configuration or an issue in cibuildwheel itself.

  + DYLD_LIBRARY_PATH=/Users/runner/work/pygit2/pygit2/ci/lib delocate-wheel --require-archs x86_64,arm64 -w /private/var/folders/1b/_r1lmxr92j54bq1tx8b953mw0000gn/T/cibw-run-wyo_rigg/cp310-macosx_universal2/repaired_wheel /private/var/folders/1b/_r1lmxr92j54bq1tx8b953mw0000gn/T/cibw-run-wyo_rigg/cp310-macosx_universal2/built_wheel/pygit2-1.16.0-cp310-cp310-macosx_10_9_universal2.whl
NotImplementedError: 
This function does not support separate values per-architecture: {
    'x86_64': [
        ('@rpath/libcrypto.3.dylib', '3.0.0', '3.0.0'),
        ('/usr/lib/libSystem.B.dylib', '1.0.0', '1351.0.0')
    ],
    'arm64': [
        ('@rpath/libcrypto.3.dylib', '3.0.0', '3.0.0'),
        ('/usr/lib/libz.1.dylib', '1.0.0', '1.2.12'),
        ('/usr/lib/libSystem.B.dylib', '1.0.0', '1351.0.0')
    ]
}

[Spitfire1900]

Opened pypa/cibuildwheel#2121 on this