Fix mypy error (surfaced after merge)

lib/galaxy/managers/jobs.py

@@ -110,7 +110,7 @@ def __init__(self, app: StructuredApp):
 
     def index_query(
         self, trans: ProvidesUserContext, payload: JobIndexQueryPayload
-    ) -> Optional[sqlalchemy.engine.Result]:
+    ) -> Optional[sqlalchemy.engine.ScalarResult]:
         """The caller is responsible for security checks on the resulting job if
         history_id, invocation_id, or implicit_collection_jobs_id is set.
         Otherwise this will only return the user's jobs or all jobs if the requesting