**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
with create_session() as session:
            session.query(SerializedDagModel).filter(
                SerializedDagModel.dag_id == 'test_verify_integrity_if_dag_changed'
            ).delete(synchronize_session=False)
        dag = DAG(dag_id='test_verify_integrity_if_dag_changed', start_date=DEFAULT_DATE)
        BashOperator(task_id='dummy', dag=dag, owner='airflow', bash_command='echo hi')
        scheduler = SchedulerJob(subdir=os.devnull)
        scheduler.dagbag.bag_dag(dag, root_dag=dag)
        scheduler.dagbag.sync_to_db()
        session = settings.Session()
        orm_dag = session.query(DagModel).get(dag.dag_id)
        assert orm_dag is not None
        scheduler = SchedulerJob(subdir=os.devnull)
        scheduler.processor_agent = mock.MagicMock()
        dag = scheduler.dagbag.get_dag('test_verify_integrity_if_dag_changed', session=session)
        scheduler._create_dag_runs([orm_dag], session)
        drs = DagRun.find(dag_id=dag.dag_id, session=session)
        assert len(drs) == 1
        dr = drs[0]
        dag_version_1 = SerializedDagModel.get_latest_version_hash(dr.dag_id, session=session)
        assert dr.dag_hash == dag_version_1
        assert scheduler.dagbag.dags == {'test_verify_integrity_if_dag_changed': dag}