**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 self._task_id
    @property
    def execution_date(self) -> datetime:
        return self._execution_date
    @property
    def start_date(self) -> datetime:
        return self._start_date
    @property
    def end_date(self) -> datetime:
        return self._end_date
    @property
    def try_number(self) -> int:
        return self._try_number
    @property
    def state(self) -> str:
        return self._state
    @property
    def pool(self) -> str:
        return self._pool
    @property
    def priority_weight(self) -> Optional[int]:
        return self._priority_weight
    @property
    def queue(self) -> str:
        return self._queue
    @property
    def key(self) -> TaskInstanceKey:
        return self._key
    @property
    def executor_config(self):