**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,
)
```
airflow/jobs/scheduler_job.py
open_slots,
                num_ready,
            )
            priority_sorted_task_instances = sorted(
                task_instances, key=lambda ti: (-ti.priority_weight, ti.execution_date)
            )
            num_starving_tasks = 0
            for current_index, task_instance in enumerate(priority_sorted_task_instances):
                if open_slots <= 0:
                    self.log.info("Not scheduling since there are %s open slots in pool %s", open_slots, pool)
                    
                    num_unhandled = len(priority_sorted_task_instances) - current_index
                    num_starving_tasks += num_unhandled
                    num_starving_tasks_total += num_unhandled
                    break
                
                
                dag_id = task_instance.dag_id
                current_dag_concurrency = dag_concurrency_map[dag_id]
                dag_concurrency_limit = task_instance.dag_model.concurrency
                self.log.info(
                    "DAG %s has %s/%s running and queued tasks",
                    dag_id,
                    current_dag_concurrency,
                    dag_concurrency_limit,
                )
                if current_dag_concurrency >= dag_concurrency_limit:
                    self.log.info(
                        "Not executing %s since the number of tasks running or queued "
                        "from DAG %s is >= to the DAG's task concurrency limit of %s",