Remove tests for unsupported Python versions in Django 5.0

Author: bobtabor-msft

.github/workflows/python-test.yaml

@@ -14,7 +14,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ["ubuntu-20.04"]
-        python_version: ["3.8", "3.9", "3.10", "3.11"]
+        python_version: ["3.10", "3.11"]
     services:
       postgres:
         image: postgres:12