django 5.1a1 test

Author: vitalik

.github/workflows/test_full.yml

@@ -12,7 +12,7 @@ jobs:
     strategy:
       matrix:
         python-version: ['3.7', '3.8', '3.9', '3.10', '3.11', '3.12']
-        django-version: ['<3.2', '<3.3', '<4.2', '<4.3', '<5.1', '5.1a1']
+        django-version: ['<3.2', '<3.3', '<4.2', '<4.3', '<5.1', '==5.1a1']
         exclude:
           - python-version: '3.7'
             django-version: '<5.1'