Fix typo on supported Django (v5)

Author: stephane

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = webstack-django-sorting
-version = 2.3.0
+version = 2.3.1
 author = Stéphane Raimbault
 author_email = stephane.raimbault@webstack.fr
 description = Easy sorting of tables with Django
@@ -22,4 +22,4 @@ classifiers =
 packages = find:
 python_requires = >=3.6
 install_requires =
-	Django>=3.0,<5.0
+	Django>=3.0,<6.0