Remove explicit testing of Python 3.8 and 3.9.

Author: adamghill

.github/workflows/python.yml

@@ -39,7 +39,8 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.8, 3.9, "3.10", "3.11"]
+        python-version: ["3.10", "3.11", "3.12"]
+        django-version: ["4.1", "4.2", "5.0"]
 
     steps:
       - uses: actions/checkout@v3