add Django 4.0 compatibility

setup.py

@@ -41,8 +41,8 @@
         "Framework :: Wagtail :: 2",
     ],
     install_requires=[
-        "Django>=3.0,<4.0",
-        "Wagtail>=2.14,<2.18",
+        "Django>=3.0,<5.0",
+        "Wagtail>=2.14,<=3.0",
     ],
     extras_require={
         "testing": ["dj-database-url==0.5.0", "freezegun==0.3.15"],

wagtail_hallo/test/urls.py

@@ -1,13 +1,13 @@
-from django.conf.urls import include, url
+from django.urls import include, path
 from django.contrib import admin
 
 from wagtail.admin import urls as wagtailadmin_urls
 from wagtail.documents import urls as wagtaildocs_urls
 from wagtail.core import urls as wagtail_urls
 
 urlpatterns = [
-    url(r"^django-admin/", admin.site.urls),
-    url(r"^admin/", include(wagtailadmin_urls)),
-    url(r"^documents/", include(wagtaildocs_urls)),
-    url(r"", include(wagtail_urls)),
+    path('django-admin/', admin.site.urls),
+    path('admin/', include(wagtailadmin_urls)),
+    path('documents/', include(wagtaildocs_urls)),
+    path('', include(wagtail_urls)),
 ]