create_user: Add 'durable=True' to the outermost transaction.

We need to specify savepoint=False explicitly in the one subroutine
that already specifies a transaction.

zerver/actions/create_user.py

@@ -487,6 +487,7 @@ def notify_created_bot(user_profile: UserProfile) -> None:
     send_event_on_commit(user_profile.realm, event, bot_owner_user_ids(user_profile))
 
 
+@transaction.atomic(durable=True)
 def do_create_user(
     email: str,
     password: str | None,
@@ -516,7 +517,6 @@ def do_create_user(
     if settings.BILLING_ENABLED:
         from corporate.lib.stripe import RealmBillingSession
 
-    with transaction.atomic():
     user_profile = create_user(
         email=email,
         password=password,
@@ -556,9 +556,7 @@ def do_create_user(
         # If this user just created a realm, make sure they are
         # properly tagged as the creator of the realm.
         realm_creation_audit_log = (
-                RealmAuditLog.objects.filter(
-                    event_type=AuditLogEventType.REALM_CREATED, realm=realm
-                )
+            RealmAuditLog.objects.filter(event_type=AuditLogEventType.REALM_CREATED, realm=realm)
             .order_by("id")
             .last()
         )

zerver/lib/onboarding.py

@@ -229,7 +229,7 @@ def send_welcome_bot_response(send_request: SendMessageRequest) -> None:
     )
 
 
-@transaction.atomic
+@transaction.atomic(savepoint=False)
 def send_initial_realm_messages(realm: Realm) -> None:
     # Sends the initial messages for a new organization.
     #