**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
super().__init__()
        self.dag_id = task.dag_id
        self.task_id = task.task_id
        self.task = task
        self.refresh_from_task(task)
        self._log = logging.getLogger("airflow.task")
        
        if execution_date and not timezone.is_localized(execution_date):
            self.log.warning(
                "execution date %s has no timezone information. Using default from dag or system",
                execution_date,
            )
            if self.task.has_dag():
                execution_date = timezone.make_aware(execution_date, self.task.dag.timezone)
            else:
                execution_date = timezone.make_aware(execution_date)
            execution_date = timezone.convert_to_utc(execution_date)
        self.execution_date = execution_date
        self.try_number = 0
        self.unixname = getuser()
        if state: