misc: remove compatibility code with old authentic version (#72025)

src/authentic2_cut/apps.py

@@ -35,12 +35,7 @@ class AppConfig(django.apps.AppConfig):
     def post_migrate(self, verbosity=2, interactive=True, using=DEFAULT_DB_ALIAS, **kwargs):
         # create custom operations
         from authentic2.a2_rbac.models import Operation
-
-        try:
-            from authentic2.a2_rbac.utils import get_operation
-        except ImportError:
-            # legacy
-            from django_rbac.utils import get_operation
+        from authentic2.a2_rbac.utils import get_operation
 
         if not router.allow_migrate(using, Operation):
             return

src/authentic2_cut/utils.py

@@ -11,16 +11,10 @@ from authentic2.a2_rbac.models import (
 )
 from authentic2.a2_rbac.models import OrganizationalUnit as OU
 from authentic2.a2_rbac.models import Permission, Role
+from authentic2.a2_rbac.utils import get_operation
 from django.contrib.auth import get_user_model
 from django.contrib.contenttypes.models import ContentType
 
-try:
-    from authentic2.a2_rbac.utils import get_operation
-except ImportError:
-    # legacy
-    from django_rbac.utils import get_operation
-
-
 User = get_user_model()