**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, expected_query_counts, dag_count, task_count, start_ago, schedule_interval, shape
    ):
        with mock.patch.dict(
            "os.environ",
            {
                "PERF_DAGS_COUNT": str(dag_count),
                "PERF_TASKS_COUNT": str(task_count),
                "PERF_START_AGO": start_ago,
                "PERF_SCHEDULE_INTERVAL": schedule_interval,
                "PERF_SHAPE": shape,
            },
        ), conf_vars(
            {
                ('scheduler', 'use_job_schedule'): 'True',
                ('core', 'store_serialized_dags'): 'True',
            }
        ):
            dagbag = DagBag(dag_folder=ELASTIC_DAG_FILE, include_examples=False)
            dagbag.sync_to_db()
            mock_agent = mock.MagicMock()
            job = SchedulerJob(subdir=PERF_DAGS_FOLDER, num_runs=1)
            job.executor = MockExecutor(do_update=False)
            job.heartbeat = mock.MagicMock()
            job.processor_agent = mock_agent
            for expected_query_count in expected_query_counts:
                with create_session() as session:
                    with assert_queries_count(expected_query_count):
                        job._do_scheduling(session)