**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
"""
        Test that the dag file processor gracefully logs an exception if there is a problem
        sending an email
        """
        session = settings.Session()
        
        mock_send_email.side_effect = RuntimeError('Could not send an email')
        test_start_date = days_ago(2)
        dag = DAG(
            dag_id='test_sla_miss',
            default_args={'start_date': test_start_date, 'sla': datetime.timedelta(days=1)},
        )
        task = DummyOperator(
            task_id='dummy', dag=dag, owner='airflow', email='test@test.com', sla=datetime.timedelta(hours=1)
        )
        session.merge(TaskInstance(task=task, execution_date=test_start_date, state='Success'))
        
        session.merge(SlaMiss(task_id='dummy', dag_id='test_sla_miss', execution_date=test_start_date))
        mock_log = mock.MagicMock()
        dag_file_processor = DagFileProcessor(dag_ids=[], log=mock_log)
        dag_file_processor.manage_slas(dag=dag, session=session)
        mock_log.exception.assert_called_once_with(
            'Could not send SLA Miss email notification for DAG %s', 'test_sla_miss'
        )
        mock_stats_incr.assert_called_once_with('sla_email_notification_failure')
    def test_dag_file_processor_sla_miss_deleted_task(self):