**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
self, initial_task_state, expected_task_state
    ):
        session = settings.Session()
        dag_id = 'test_execute_helper_should_change_state_for_tis_without_dagrun'
        dag = DAG(dag_id, start_date=DEFAULT_DATE, default_args={'owner': 'owner1'})
        with dag:
            op1 = DummyOperator(task_id='op1')
        
        dagbag = DagBag(dag_folder="/dev/null", include_examples=False, read_dags_from_db=False)
        dagbag.bag_dag(dag, root_dag=dag)
        dagbag.sync_to_db()
        dag = DagBag(read_dags_from_db=True, include_examples=False).get_dag(dag_id)
        
        dag.clear()
        dr = dag.create_dagrun(
            run_type=DagRunType.SCHEDULED,