Upgrade django-modelcluster to 5.2

setup.py

@@ -21,7 +21,7 @@ except ImportError:
 
 install_requires = [
     "Django>=3.0,<3.3",
-    "django-modelcluster>=5.1,<6.0",
+    "django-modelcluster>=5.2,<6.0",
     "django-taggit>=1.0,<2.0",
     "django-treebeard>=4.2.0,<5.0,!=4.5",
     "djangorestframework>=3.11.1,<4.0",