CI: use pytest-github-actions-annotate-failures

.github/workflows/django-tests.yml

@@ -35,6 +35,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install -r requirements.txt
+        pip install pytest-github-actions-annotate-failures
     - name: Set up .env
       run: mv .env.example .env
     - name: Check migrations up-to-date