**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 if a dag run exists, scheduler._create_dag_runs does not raise an error.
        And if a Dag Run does not exist it creates next Dag Run. In both cases the Scheduler
        sets next execution date as DagModel.next_dagrun
        """
        dag = DAG(
            dag_id='test_scheduler_create_dag_runs_check_existing_run',
            start_date=DEFAULT_DATE,
            schedule_interval=timedelta(days=1),
        )
        DummyOperator(
            task_id='dummy',
            dag=dag,
        )
        session = settings.Session()
        assert dag.get_last_dagrun(session) is None
        dagbag = DagBag(
            dag_folder=os.devnull,