actions: Use 'durable=True' in outermost transaction.atomic block.

We used 'savepoint=False' in #31169 which was prior to our discussion
in CZO to use 'durable=True' instead.

This commit makes changes to use 'durable=True' in the outermost
transaction.atomic block.

zerver/actions/alert_words.py

@@ -12,13 +12,13 @@ def notify_alert_words(user_profile: UserProfile, words: Sequence[str]) -> None:
     send_event_on_commit(user_profile.realm, event, [user_profile.id])
 
 
-@transaction.atomic(savepoint=False)
+@transaction.atomic(durable=True)
 def do_add_alert_words(user_profile: UserProfile, alert_words: Iterable[str]) -> None:
     words = add_user_alert_words(user_profile, alert_words)
     notify_alert_words(user_profile, words)
 
 
-@transaction.atomic(savepoint=False)
+@transaction.atomic(durable=True)
 def do_remove_alert_words(user_profile: UserProfile, alert_words: Iterable[str]) -> None:
     words = remove_user_alert_words(user_profile, alert_words)
     notify_alert_words(user_profile, words)

zerver/actions/scheduled_messages.py

@@ -93,7 +93,7 @@ def do_schedule_messages(
 
         scheduled_messages.append((scheduled_message, send_request))
 
-    with transaction.atomic():
+    with transaction.atomic(durable=True):
         ScheduledMessage.objects.bulk_create(
             [scheduled_message for scheduled_message, ignored in scheduled_messages]
         )

zerver/actions/user_status.py

@@ -7,7 +7,7 @@ from zerver.models import UserProfile
 from zerver.tornado.django_api import send_event_on_commit
 
 
-@transaction.atomic(savepoint=False)
+@transaction.atomic(durable=True)
 def do_update_user_status(
     user_profile: UserProfile,
     away: bool | None,