**Description**

I have noticed that the stable REST API doesn't have the ability to run a task (which is possible from the airflow web interface.
I think it would be nice to have either:
- Run task 
- Run all failing tasks (rerun from point of failure)
this ability for integrations.

**Use case / motivation**

I would like the ability to identify the failing tasks on a specific DAG Run and rerun only them.
I would like to do it remotely (non-interactive) using the REST API.
I could write a script that run only the failing tasks, but I couldn't find a way to "Run" a task, when I have the task instance ID.

**Are you willing to submit a PR?**

Not at this stage

**Related Issues**



airflow/models/dag.py
"""
        Return (and lock) a list of Dag objects that are due to create a new DagRun.
        This will return a resultset of rows  that is row-level-locked with a "SELECT ... FOR UPDATE" query,
        you should ensure that any scheduling decisions are made in a single transaction -- as soon as the
        transaction is committed it will be unlocked.
        """
        
        
        
        query = (
            session.query(cls)
            .filter(
                cls.is_paused.is_(False),
                cls.is_active.is_(True),
                cls.next_dagrun_create_after <= func.now(),
            )
            .order_by(cls.next_dagrun_create_after)
            .limit(cls.NUM_DAGS_PER_DAGRUN_QUERY)
        )
        return with_row_locks(query, of=cls, session=session, **skip_locked(session=session))
    def calculate_dagrun_date_fields(