### 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
old_job = SchedulerJob(subdir=os.devnull)
        old_job.state = State.RUNNING
        old_job.latest_heartbeat = timezone.utcnow() - timedelta(minutes=15)
        session.add(old_job)
        session.flush()
        dr1 = dag_maker.create_dagrun(
            run_type=DagRunType.SCHEDULED,
            execution_date=DEFAULT_DATE,
            start_date=timezone.utcnow(),
        )
        ti1, ti2 = dr1.get_task_instances(session=session)
        dr1.state = State.RUNNING
        ti1.state = State.QUEUED
        ti1.queued_by_job_id = old_job.id
        session.merge(dr1)
        session.merge(ti1)
        ti2.state = State.QUEUED
        ti2.queued_by_job_id = self.scheduler_job.id
        session.merge(ti2)
        session.flush()
        num_reset_tis = self.scheduler_job.adopt_or_reset_orphaned_tasks(session=session)
        assert 1 == num_reset_tis
        session.refresh(ti1)
        assert ti1.state is None
        session.refresh(ti2)
        assert ti2.state == State.QUEUED
        session.rollback()
        if old_job.processor_agent:
            old_job.processor_agent.end()
    def test_adopt_or_reset_orphaned_tasks_only_fails_scheduler_jobs(self, caplog):