fix: use automatic transaction commit in provider update handler

The provider update handler was missing proper transaction handling,
causing quota deductions to be lost. This fix uses session.begin()
context manager for automatic commit/rollback, ensuring provider
quota updates are properly persisted.

Fixes #24356

api/events/event_handlers/update_provider_when_message_created.py

@@ -188,7 +188,7 @@ def _execute_provider_updates(updates_to_perform: list[_ProviderUpdateOperation]
 
     # Use SQLAlchemy's context manager for transaction management
     # This automatically handles commit/rollback
-    with Session(db.engine) as session:
+    with Session(db.engine) as session, session.begin():
         # Use a single transaction for all updates
         for update_operation in updates_to_perform:
             filters = update_operation.filters