**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/dag.py
recursion_depth=recursion_depth,
                    max_recursion_depth=max_recursion_depth,
                    dag_bag=dag_bag,
                    visited_external_tis=visited_external_tis,
                )
            )
        if start_date:
            tis = tis.filter(TI.execution_date >= start_date)
        if end_date:
            tis = tis.filter(TI.execution_date <= end_date)
        if only_failed:
            tis = tis.filter(or_(TI.state == State.FAILED, TI.state == State.UPSTREAM_FAILED))
        if only_running:
            tis = tis.filter(TI.state == State.RUNNING)
        if task_ids:
            tis = tis.filter(TI.task_id.in_(task_ids))
        if include_subdags:
            from airflow.sensors.external_task import ExternalTaskMarker
            
            instances = tis.all()
            for ti in instances:
                if ti.operator == ExternalTaskMarker.__name__:
                    if visited_external_tis is None:
                        visited_external_tis = set()
                    ti_key = ti.key.primary
                    if ti_key not in visited_external_tis:
                        
                        
                        task: ExternalTaskMarker = cast(
                            ExternalTaskMarker, copy.copy(self.get_task(ti.task_id))