Refs #33561 -- Made created=True required in signature of RemoteUserBackend.configure_user() subclasses.

Per deprecation timeline.

django/contrib/auth/backends.py

@@ -1,10 +1,6 @@
-import warnings
-
 from django.contrib.auth import get_user_model
 from django.contrib.auth.models import Permission
 from django.db.models import Exists, OuterRef, Q
-from django.utils.deprecation import RemovedInDjango50Warning
-from django.utils.inspect import func_supports_parameter
 
 UserModel = get_user_model()
 
@@ -211,19 +207,7 @@ class RemoteUserBackend(ModelBackend):
                 user = UserModel._default_manager.get_by_natural_key(username)
             except UserModel.DoesNotExist:
                 pass
-
-        # RemovedInDjango50Warning: When the deprecation ends, replace with:
-        #   user = self.configure_user(request, user, created=created)
-        if func_supports_parameter(self.configure_user, "created"):
-            user = self.configure_user(request, user, created=created)
-        else:
-            warnings.warn(
-                f"`created=True` must be added to the signature of "
-                f"{self.__class__.__qualname__}.configure_user().",
-                category=RemovedInDjango50Warning,
-            )
-            if created:
-                user = self.configure_user(request, user)
+        user = self.configure_user(request, user, created=created)
         return user if self.user_can_authenticate(user) else None
 
     def clean_username(self, username):