### Body

The `test_no_orphan_process_will_be_left` in `TestSchedulerJob` is really flaky.

Before we know how to fix it, I will quarantine it:

https://github.com/apache/airflow/pull/18691/checks?check_run_id=3811660138

```
  =================================== FAILURES ===================================
  _____________ TestSchedulerJob.test_no_orphan_process_will_be_left _____________
  
  self = <tests.jobs.test_scheduler_job.TestSchedulerJob object at 0x7fc2f91d2ac8>
  
      def test_no_orphan_process_will_be_left(self):
          empty_dir = mkdtemp()
          current_process = psutil.Process()
          old_children = current_process.children(recursive=True)
          self.scheduler_job = SchedulerJob(
              subdir=empty_dir, num_runs=1, executor=MockExecutor(do_update=False)
          )
          self.scheduler_job.run()
          shutil.rmtree(empty_dir)
      
          # Remove potential noise created by previous tests.
          current_children = set(current_process.children(recursive=True)) - set(old_children)
  >       assert not current_children
  E       AssertionError: assert not {psutil.Process(pid=2895, name='pytest', status='running', started='06:53:45')}
  
```

### Committer

- [X] I acknowledge that I am a maintainer/committer of the Apache Airflow project.
tests/jobs/test_scheduler_job.py
res = self.scheduler_job._executable_task_instances_to_queued(max_tis=32, session=session)
        assert 1 == len(res)
        ti1_2.state = State.RUNNING
        ti1_3 = dr3.get_task_instance(task1.task_id)
        ti1_3.state = State.SCHEDULED
        session.merge(ti1_2)
        session.merge(ti1_3)
        session.flush()
        res = self.scheduler_job._executable_task_instances_to_queued(max_tis=32, session=session)
        assert 0 == len(res)
        ti1_1.state = State.SCHEDULED
        ti1_2.state = State.SCHEDULED
        ti1_3.state = State.SCHEDULED
        session.merge(ti1_1)
        session.merge(ti1_2)
        session.merge(ti1_3)
        session.flush()
        res = self.scheduler_job._executable_task_instances_to_queued(max_tis=32, session=session)
        assert 2 == len(res)
        ti1_1.state = State.RUNNING
        ti1_2.state = State.SCHEDULED
        ti1_3.state = State.SCHEDULED
        session.merge(ti1_1)
        session.merge(ti1_2)
        session.merge(ti1_3)
        session.flush()
        res = self.scheduler_job._executable_task_instances_to_queued(max_tis=32, session=session)
        assert 1 == len(res)
        session.rollback()
    def test_change_state_for_executable_task_instances_no_tis_with_state(self, dag_maker):