Attempt to fix CI

Author: arvkevi

.github/workflows/tests.yml

@@ -10,6 +10,12 @@ jobs:
       matrix:
         python-version: ["3.7", "3.8", "3.9", "3.10", "3.11"]
         os: [ubuntu-latest, macos-latest, windows-latest]
+        exclude:  # Python < v3.8 does not support Apple Silicon ARM64.
+        - python: "3.7"
+          os: macos-latest
+        include:  # So run those legacy versions on Intel CPUs.
+        - python: "3.7"
+          os: macos-13
     env:
       OS: ${{ matrix.os }}
       PYHTHON: ${{ matrix.python-version }}