**Apache Airflow version**:

1.10.12

**What happened**:

I created dag with dagrun_timeout=2 minutes. 

After 2 minutes dagrun is marked as failed and the next one is started, but task keeps going.

**What you expected to happen**:

Task is killed with dag run as it is done when you mark dagrun failed manually.

**How to reproduce it**:
```
dag = DAG(dag_id='platform.airflow-test',
          description='',
          schedule_interval="0 0 * * *",
          start_date=datetime(2020, 7, 1),
          max_active_runs=1,
          catchup=True,
          dagrun_timeout=timedelta(minutes=2))

run_this = BashOperator(
    task_id='run_after_loop',
    bash_command=' for((i=1;i<=600;i+=1)); do echo "Welcome $i times"; sleep 1;  done',
    dag=dag,
)
```
tests/jobs/test_scheduler_job.py
assert dr.state == State.FAILED
        expected_callback = DagCallbackRequest(
            full_filepath=dr.dag.fileloc,
            dag_id=dr.dag_id,
            is_failure_callback=True,
            execution_date=dr.execution_date,
            msg="timed_out",
        )
        
        scheduler.processor_agent.send_callback_to_execute.assert_called_once_with(expected_callback)
        session.rollback()
        session.close()
    @parameterized.expand([(State.SUCCESS, "success"), (State.FAILED, "task_failure")])
    def test_dagrun_callbacks_are_called(self, state, expected_callback_msg):
        """
        Test if DagRun is successful, and if Success callbacks is defined, it is sent to DagFileProcessor.
        Also test that SLA Callback Function is called.
        """
        dag = DAG(
            dag_id='test_dagrun_callbacks_are_called',
            start_date=DEFAULT_DATE,
            on_success_callback=lambda x: print("success"),
            on_failure_callback=lambda x: print("failed"),
        )
        DummyOperator(task_id='dummy', dag=dag, owner='airflow')
        scheduler = SchedulerJob(subdir=os.devnull)
        scheduler.processor_agent = mock.Mock()
        scheduler.processor_agent.send_callback_to_execute = mock.Mock()
        scheduler._send_sla_callbacks_to_processor = mock.Mock()