fixup! Run Task failure callbacks on DAG Processor when task is externally killed

Author: kaxil

airflow-core/src/airflow/api_fastapi/execution_api/datamodels/taskinstance.py

@@ -301,7 +301,7 @@ class TIRunContext(BaseModel):
     dag_run: DagRun
     """DAG run information for the task instance."""
 
-    task_reschedule_count: Annotated[int, Field(default=0)]
+    task_reschedule_count: int = 0
     """How many times the task has been rescheduled."""
 
     max_tries: int

airflow-core/src/airflow/jobs/scheduler_job_runner.py

@@ -931,6 +931,9 @@ def process_executor_events(
                         context_from_server=TIRunContext(
                             dag_run=ti.dag_run,
                             max_tries=ti.max_tries,
+                            variables=[],
+                            connections=[],
+                            xcom_keys_to_clear=[],
                         ),
                     )
                     executor.send_callback(request)
@@ -2290,6 +2293,9 @@ def _purge_task_instances_without_heartbeats(
                 context_from_server=TIRunContext(
                     dag_run=ti.dag_run,
                     max_tries=ti.max_tries,
+                    variables=[],
+                    connections=[],
+                    xcom_keys_to_clear=[],
                 ),
             )
             session.add(