**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
'task_ids',
        'parent_dag',
        'start_date',
        'schedule_interval',
        'full_filepath',
        'template_searchpath',
        'last_loaded',
    }
    __serialized_fields: Optional[FrozenSet[str]] = None
    def __init__(
        self,
        dag_id: str,
        description: Optional[str] = None,
        schedule_interval: Optional[ScheduleInterval] = timedelta(days=1),
        start_date: Optional[datetime] = None,
        end_date: Optional[datetime] = None,
        full_filepath: Optional[str] = None,
        template_searchpath: Optional[Union[str, Iterable[str]]] = None,
        template_undefined: Type[jinja2.StrictUndefined] = jinja2.StrictUndefined,
        user_defined_macros: Optional[Dict] = None,
        user_defined_filters: Optional[Dict] = None,
        default_args: Optional[Dict] = None,
        concurrency: int = conf.getint('core', 'dag_concurrency'),
        max_active_runs: int = conf.getint('core', 'max_active_runs_per_dag'),
        dagrun_timeout: Optional[timedelta] = None,
        sla_miss_callback: Optional[Callable] = None,
        default_view: str = conf.get('webserver', 'dag_default_view').lower(),
        orientation: str = conf.get('webserver', 'dag_orientation'),
        catchup: bool = conf.getboolean('scheduler', 'catchup_by_default'),
        on_success_callback: Optional[DagStateChangeCallback] = None,