**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
"""This method is deprecated in favor of partial_subset"""
        warnings.warn(
            "This method is deprecated and will be removed in a future version. Please use partial_subset",
            DeprecationWarning,
            stacklevel=2,
        )
        return self.partial_subset(*args, **kwargs)
    def partial_subset(
        self,
        task_ids_or_regex: Union[str, PatternType, Iterable[str]],
        include_downstream=False,
        include_upstream=True,
        include_direct_upstream=False,
    ):
        """
        Returns a subset of the current dag as a deep copy of the current dag
        based on a regex that should match one or many tasks, and includes
        upstream and downstream neighbours based on the flag passed.
        :param task_ids_or_regex: Either a list of task_ids, or a regex to
            match against task ids (as a string, or compiled regex pattern).
        :type task_ids_or_regex: [str] or str or re.Pattern
        :param include_downstream: Include all downstream tasks of matched
            tasks, in addition to matched tasks.
        :param include_upstream: Include all upstream tasks of matched tasks,