Update test matrix to use Django 5.2 stable version (#9679)

Author: TGoddessana

tox.ini

@@ -19,7 +19,7 @@ deps =
         django42: Django>=4.2,<5.0
         django50: Django>=5.0,<5.1
         django51: Django>=5.1,<5.2
-        django52: Django>=5.2b1,<6.0
+        django52: Django>=5.2,<6.0
         djangomain: https://github.com/django/django/archive/main.tar.gz
         -rrequirements/requirements-testing.txt
         -rrequirements/requirements-optionals.txt