Add django 5.1 to the test matrix and add its classifier

.github/workflows/test.yml

@@ -133,7 +133,7 @@ jobs:
       fail-fast: false
       matrix:
         python-version: ['3.11', '3.12']
-        django-version: ['4.2', '5.0']
+        django-version: ['4.2', '5.0', '5.1']
         include:
           - python-version: '3.8'
             django-version: '4.2'

CONTRIBUTING.md

@@ -132,6 +132,7 @@ This rule helps us avoid tying in too closely to Django’s undocumented interna
     - Update `django-stubs-ext>=` dependency in root `setup.py` to the same version number.
     - Add a new row at the top of ['Version compatibility' table in README.md](README.md#version-compatibility).
     - Use pull request title "Version x.y.z release" by convention.
+    - Add the correct classifiers to `setup.py` if support is added for a new Python or Django version
 
 2. Ensure the CI succeeds. A maintainer must merge this PR. If it's just a version bump, no need
    to wait for a second maintainer's approval.

setup.py

@@ -71,6 +71,7 @@ def find_stub_files(name: str) -> List[str]:
         "Framework :: Django",
         "Framework :: Django :: 4.2",
         "Framework :: Django :: 5.0",
+        "Framework :: Django :: 5.1",
     ],
     project_urls={
         "Funding": "https://github.com/sponsors/typeddjango",