update django version

Author: methane

.github/workflows/tests.yaml

@@ -68,7 +68,7 @@ jobs:
     env:
       PIP_NO_PYTHON_VERSION_WARNING: 1
       PIP_DISABLE_PIP_VERSION_CHECK: 1
-      DJANGO_VERSION: "4.2.16"
+      DJANGO_VERSION: "4.2.28"
     steps:
       - name: Start MySQL
         run: |