test: add Django 5.2 to tox runs

Author: browniebroke

tox.ini

@@ -16,10 +16,10 @@
 # When changing this, also update the classifiers in setup.py:
 envlist =
     py39-django{22,32,42}-cov{6,7,tip},
-    py310-django{32,42,51}-cov{6,7,tip},
-    py311-django{42,51}-cov{6,7,tip},
-    py312-django{51,tip}-cov{7,tip},
-    py313-django{51,tip}-cov{7,tip},
+    py310-django{32,42,51,52}-cov{6,7,tip},
+    py311-django{42,51,52}-cov{6,7,tip},
+    py312-django{51,52,tip}-cov{7,tip},
+    py313-django{51,52,tip}-cov{7,tip},
     check,pkgcheck,doc
 
 [testenv]
@@ -31,6 +31,7 @@ deps =
     django32: Django>=3.2,<4.0
     django42: Django>=4.2,<5.0
     django51: Django>=5.1,<5.2
+    django52: Django>=5.2,<6.0
     djangotip: git+https://github.com/django/django.git
     pytest
     unittest-mixins==1.6