Stop testing on Django 5.0 and 5.1 with Python 3.9

.github/workflows/test.yaml

@@ -16,7 +16,9 @@ jobs:
         django: ["djagno==4.2", "django==5.0", "django==5.1"]
         exclude:
           - python: "3.9"
-            django: ["django==5.0", "django==5.1"]
+            django: "django==5.0"
+          - python: "3.9"
+            django: "django==5.1"
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-python@v3