fix duplicate user

enrollments-events/app/events/reenroll_on_failed.py

@@ -13,8 +13,6 @@ from config import ENROLLMENT_TABLE
 from enrollment import (
     Course,
     Enrollment,
-    Kind,
-    LinkedEntity,
     SubscriptionFrozenError,
     User,
     enroll,
@@ -64,14 +62,7 @@ def lambda_handler(event: EventBridgeEvent, context: LambdaContext) -> bool:
             # Reuse the deduplication window if it exists
             deduplication_window={'offset_days': offset_days} if offset_days else None,
             # The enrollment must know its source
-            linked_entities=frozenset(
-                {
-                    LinkedEntity(
-                        id=new_image['id'],
-                        kind=Kind.ENROLLMENT,
-                    ),
-                },
-            ),
+            parent_entity=new_image['id'],
             persistence_layer=dyn,
         )
     except SubscriptionFrozenError: