Fix the type hint for tis_query in _process_executor_events (apache#3…

…6655)

airflow/jobs/scheduler_job_runner.py

@@ -706,13 +706,13 @@ def _process_executor_events(self, session: Session) -> int:
         query = select(TI).where(filter_for_tis).options(selectinload(TI.dag_model))
         # row lock this entire set of taskinstances to make sure the scheduler doesn't fail when we have
         # multi-schedulers
-        tis: Iterator[TI] = with_row_locks(
+        tis_query: Query = with_row_locks(
             query,
             of=TI,
             session=session,
             **skip_locked(session=session),
         )
-        tis = session.scalars(tis)
+        tis: Iterator[TI] = session.scalars(tis_query)
         for ti in tis:
             try_number = ti_primary_key_to_try_number_map[ti.key.primary]
             buffer_key = ti.key.with_try_number(try_number)