**Apache Airflow version**:

2.0.1

**What happened**:

When clearing task across dags using `ExternalTaskMarker` the dag state of the external `DagRun` is not set to active. So cleared tasks in the external dag will not automatically start if the `DagRun` is a Failed or Succeeded state.

**What you expected to happen**:

The external `DagRun` run should also be set to Running state.

**How to reproduce it**:

Clear tasks in an external dag using an ExternalTaskMarker.


**Anything else we need to know**:

Looking at the code is has:

https://github.com/apache/airflow/blob/b23fc137812f5eabf7834e07e032915e2a504c17/airflow/models/dag.py#L1323-L1335

It seems like it intentionally calls the dag member method `set_dag_run_state` instead of letting the helper function `clear_task_insntances` set the `DagRun` state. But the member method will only change the state of `DagRun`s of dag where the original task is, while I believe `clear_task_instances` would correctly change the state of all involved `DagRun`s.

airflow/models/taskinstance.py
return None
        
        first = list(tis)[0]
        dag_id = first.dag_id
        execution_date = first.execution_date
        first_task_id = first.task_id
        
        
        if all(t.dag_id == dag_id and t.execution_date == execution_date for t in tis):
            return and_(
                TaskInstance.dag_id == dag_id,
                TaskInstance.execution_date == execution_date,
                TaskInstance.task_id.in_(t.task_id for t in tis),
            )
        if all(t.dag_id == dag_id and t.task_id == first_task_id for t in tis):
            return and_(
                TaskInstance.dag_id == dag_id,
                TaskInstance.execution_date.in_(t.execution_date for t in tis),
                TaskInstance.task_id == first_task_id,
            )
        return or_(
            and_(
                TaskInstance.dag_id == ti.dag_id,
                TaskInstance.task_id == ti.task_id,
                TaskInstance.execution_date == ti.execution_date,
            )
            for ti in tis
        )
TaskInstanceStateType = Tuple[TaskInstanceKey, str]
class SimpleTaskInstance: