**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
self,
        error: Union[str, Exception],
        test_mode: Optional[bool] = None,
        force_fail: bool = False,
        error_file: Optional[str] = None,
        session=None,
    ) -> None:
        """Handle Failure for the TaskInstance"""
        if test_mode is None:
            test_mode = self.test_mode
        if error:
            if isinstance(error, Exception):
                self.log.exception("Task failed with exception")
            else:
                self.log.error("%s", error)
            
            
            if error_file:
                set_error_file(error_file, error)
        task = self.task
        self.end_date = timezone.utcnow()