fix(deps): update dependency django-stubs to v6

Author: renovate[bot]

pyproject.toml

@@ -58,7 +58,7 @@ dependencies = [
     "django-silk>=5.3.2,<6.0.0",
     "django-split-settings>=1.2.0,<2.0.0",
     "django-storages>=1.14,<2.0",
-    "django-stubs>=5.2,<5.3",
+    "django-stubs>=6,<6.1",
     "django-tree-queries>=0.21.2",
     "django>=5.2,<5.3",
     "djangorestframework>=3.14.0,<4.0.0",