Fix up CI/CD Python versions

Author: samcmill

.github/workflows/python3.yml

@@ -8,12 +8,8 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: ['3.7', '3.8', '3.9', '3.10', '3.11', '3.12']
+        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
         include:
-          - os: macos-latest
-            python-version: '3.5'
-          - os: macos-latest
-            python-version: '3.6'
           - os: windows-latest
             python-version: '3.5'
           - os: windows-latest