Drop Django 4.2 to 5.1 support (#701)

These versions are all EOL since April.

Author: adamchainz

docs/changelog.rst

@@ -2,6 +2,11 @@
 Changelog
 =========
 
+Unreleased
+----------
+
+* Drop Django 4.2 to 5.1 support.
+
 6.12.0 (2026-02-27)
 -------------------
 

pyproject.toml

@@ -25,9 +25,6 @@ requires-python = ">=3.10"
 classifiers = [
   "Development Status :: 5 - Production/Stable",
   "Framework :: Django",
-  "Framework :: Django :: 4.2",
-  "Framework :: Django :: 5.0",
-  "Framework :: Django :: 5.1",
   "Framework :: Django :: 5.2",
   "Framework :: Django :: 6.0",
   "Intended Audience :: Developers",
@@ -63,19 +60,13 @@ docs = [
   "sphinx-build-compatibility",
   "sphinx-copybutton>=0.5.2",
 ]
-django42 = [ "django>=4.2a1,<5; python_version>='3.8'" ]
-django50 = [ "django>=5a1,<5.1; python_version>='3.10'" ]
-django51 = [ "django>=5.1a1,<5.2; python_version>='3.10'" ]
 django52 = [ "django>=5.2a1,<6; python_version>='3.10'" ]
 django60 = [ "django>=6a1,<6.1; python_version>='3.12'" ]
 
 [tool.uv]
 sources.sphinx-build-compatibility = { git = "https://github.com/readthedocs/sphinx-build-compatibility", rev = "4f304bd4562cdc96316f4fec82b264ca379d23e0" }
 conflicts = [
   [
-    { group = "django42" },
-    { group = "django50" },
-    { group = "django51" },
     { group = "django52" },
     { group = "django60" },
   ],

tox.ini

@@ -4,10 +4,10 @@ requires =
 env_list =
     py314-django{60, 52}
     py314-codegen
-    py313-django{60, 52, 51}
-    py312-django{60, 52, 51, 50, 42}
-    py311-django{52, 51, 50, 42}
-    py310-django{52, 51, 50, 42}
+    py313-django{60, 52}
+    py312-django{60, 52}
+    py311-django{52}
+    py310-django{52}
 
 [testenv]
 runner = uv-venv-lock-runner