Remove unsupported Python/Django combinations

Author: thibaudcolas

.github/workflows/ci.yml

@@ -23,14 +23,17 @@ jobs:
     strategy:
       matrix:
         include:
+          # Test with all supported Django versions, for all compatible Python versions.
+          # See https://docs.djangoproject.com/en/4.0/faq/install/#what-python-version-can-i-use-with-django for the official matrix.
+          # Additionally test on Django’s main branch with the most recent Python version.
           - python: "3.7"
             toxenv: py37-dj22,py37-dj30,py37-dj31,py37-dj32
           - python: "3.8"
             toxenv: py38-dj22,py38-dj30,py38-dj31,py38-dj32
           - python: "3.9"
-            toxenv: py39-dj22,py39-dj30,py39-dj31,py39-dj32,py39-djmain
+            toxenv: py39-dj22,py39-dj30,py39-dj31,py39-dj32
           - python: "3.10"
-            toxenv: py310-dj22,py310-dj30,py310-dj31,py310-dj32,py310-djmain
+            toxenv: py310-dj32,py310-djmain
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v2