**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
self,
        start_date: datetime,
        num: Optional[int] = None,
        end_date: Optional[datetime] = timezone.utcnow(),
    ) -> List[datetime]:
        if num is not None:
            end_date = None
        return utils_date_range(
            start_date=start_date, end_date=end_date, num=num, delta=self.normalized_schedule_interval
        )
    def is_fixed_time_schedule(self):
        """
        Figures out if the DAG schedule has a fixed time (e.g. 3 AM).
        :return: True if the schedule has a fixed time, False if not.
        """
        now = datetime.now()
        cron = croniter(self.normalized_schedule_interval, now)
        start = cron.get_next(datetime)
        cron_next = cron.get_next(datetime)
        if cron_next.minute == start.minute and cron_next.hour == start.hour:
            return True
        return False
    def following_schedule(self, dttm):