fix: possible None in query

Author: mihow

ami/main/models.py

@@ -1167,9 +1167,13 @@ def deployment_events_need_update(deployment: Deployment) -> bool:
 
     ungrouped_images = models.Q(event__isnull=True)
 
-    events_last_updated = deployment.events.aggregate(
-        latest_updated_at=models.Max("updated_at"),
-    )["latest_updated_at"]
+    events_last_updated = (
+        deployment.events.aggregate(
+            latest_updated_at=models.Max("updated_at"),
+        )["latest_updated_at"]
+        or deployment.updated_at
+        or datetime.datetime.min
+    )
     images_updated_after_events = models.Q(timestamp__gt=events_last_updated)
 
     new_or_ungrouped_images = (