**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**



tests/api_connexion/endpoints/test_task_instance_endpoint.py
if task_instances is None:
                pass
            elif update_extras:
                self.ti_extras.update(task_instances[i])
            else:
                self.ti_init.update(task_instances[i])
            ti = TaskInstance(task=tasks[i], **self.ti_init)
            for key, value in self.ti_extras.items():
                setattr(ti, key, value)
            session.add(ti)
            if single_dag_run is False:
                dr = DagRun(
                    dag_id=dag_id,
                    run_id=f"TEST_DAG_RUN_ID_{i}",
                    execution_date=self.ti_init["execution_date"],
                    run_type=DagRunType.MANUAL.value,
                    state=dag_run_state,
                )
                session.add(dr)
        if single_dag_run:
            dr = DagRun(
                dag_id=dag_id,
                run_id="TEST_DAG_RUN_ID",
                execution_date=self.default_time,
                run_type=DagRunType.MANUAL.value,
                state=dag_run_state,
            )
            session.add(dr)
        session.commit()
class TestGetTaskInstance(TestTaskInstanceEndpoint):