fix(spans-migration): add fixes for alerts rollback migration (#104469)

to make sure we roll back all alerts (even failed ones) we're checking
for the updating subscription state as well. I've also put everything in
an atomic transaction so that there won't be any half updated alerts 😢

Author: nikkikapadia

src/sentry/explore/translation/alerts_translation.py

@@ -179,8 +179,10 @@ def translate_detector_and_update_subscription_in_snuba(snuba_query: SnubaQuery)
 
 
 def rollback_detector_query_and_update_subscription_in_snuba(snuba_query: SnubaQuery):
+    # querying for updating as well just in case the subscription gets stuck in updating
     query_subscription_qs = QuerySubscription.objects.filter(
-        snuba_query_id=snuba_query.id, status=QuerySubscription.Status.ACTIVE.value
+        snuba_query_id=snuba_query.id,
+        status__in=[QuerySubscription.Status.ACTIVE.value, QuerySubscription.Status.UPDATING.value],
     )
     query_subscription = query_subscription_qs.first()
 
@@ -200,6 +202,7 @@ def rollback_detector_query_and_update_subscription_in_snuba(snuba_query: SnubaQ
     snapshot = snuba_query.query_snapshot
 
     if not snapshot:
+        logger.info("No snapshot found for snuba query %s", snuba_query.id)
         return
 
     # Skip rollback if user has already updated this alert/monitor
@@ -212,6 +215,7 @@ def rollback_detector_query_and_update_subscription_in_snuba(snuba_query: SnubaQ
     detectors = data_source.detectors.all()
 
     old_query_type, old_dataset, old_query, old_aggregate = _get_old_query_info(snuba_query)
+
     with atomic_transaction(
         using=(
             router.db_for_write(SnubaQuery),
@@ -262,4 +266,7 @@ def rollback_detector_query_and_update_subscription_in_snuba(snuba_query: SnubaQ
                 event_types=[SnubaQueryEventType.EventType.TRANSACTION],
             )
 
+    logger.info(
+        "Query successfully rolled back to legacy", extra={"snuba_query_id": snuba_query.id}
+    )
     return