Add Django upper bound to base and dist tests to avoid testing on unsupported versions

Author: browniebroke

tox.ini

@@ -28,13 +28,13 @@ deps =
 [testenv:base]
 ; Ensure optional dependencies are not required
 deps =
-        django
+        django<6.1
         -rrequirements/requirements-testing.txt
 
 [testenv:dist]
 commands = python -W error::DeprecationWarning -W error::PendingDeprecationWarning runtests.py --no-pkgroot --staticfiles {posargs}
 deps =
-        django
+        django<6.1
         -rrequirements/requirements-testing.txt
         -rrequirements/requirements-optionals.txt