GitHub Actions: Fix macOS by using an older x86 version

Author: jhasse

.github/workflows/python-package.yml

@@ -19,7 +19,7 @@ jobs:
       matrix:
         # would use windows-latest, but distutils tries to build against the version of MSVC that python was compiled with
         #   https://github.com/pypa/setuptools/blob/main/setuptools/_distutils/msvc9compiler.py#L403
-        os: [ "ubuntu-latest", "macos-latest", "windows-2019" ]
+        os: [ "ubuntu-latest", "macos-12", "windows-2019" ]
         python-version: ["3.7", "3.8", "3.9", "3.10"]
         #os: [ "ubuntu-latest" ]
         #python-version: ["3.8"]