This tests fails occasionally on mysql at least:

https://github.com/apache/airflow/pull/11555/checks?check_run_id=1260840314#step:9:1125

```
=================================== FAILURES ===================================
_____________ TestSchedulerJob.test_no_orphan_process_will_be_left _____________

self = <tests.jobs.test_scheduler_job.TestSchedulerJob testMethod=test_no_orphan_process_will_be_left>

    def test_no_orphan_process_will_be_left(self):
        empty_dir = mkdtemp()
        current_process = psutil.Process()
        old_children = current_process.children(recursive=True)
        scheduler = SchedulerJob(subdir=empty_dir,
                                 num_runs=1,
                                 executor=MockExecutor(do_update=False))
        scheduler.run()
        shutil.rmtree(empty_dir)
    
        # Remove potential noise created by previous tests.
        current_children = set(current_process.children(recursive=True)) - set(
            old_children)
>       self.assertFalse(current_children)
E       AssertionError: {psutil.Process(pid=3474, name='/usr/local/bin/', status='running', started='19:26:22')} is not false

tests/jobs/test_scheduler_job.py:871: AssertionError
```



tests/cli/commands/test_jobs_command.py
with create_session() as session:
            for _ in range(3):
                job = SchedulerJob()
                job.state = State.RUNNING
                job.hostname = 'HOSTNAME'
                session.add(job)
            session.commit()
            job.heartbeat()
        with pytest.raises(SystemExit, match=r"Found 3 alive jobs. Expected only one."):
            jobs_command.check(
                self.parser.parse_args(
                    [
                        'jobs',
                        'check',
                        '--job-type',
                        'SchedulerJob',
                        '--limit',
                        '100',
                    ]
                )
            )
    def test_should_raise_exception_for_allow_multiple_and_limit_1(self):
        with pytest.raises(
            SystemExit,
            match=r"To use option --allow-multiple, you must set the limit to a value greater than 1.",
        ):
            jobs_command.check(self.parser.parse_args(['jobs', 'check', '--allow-multiple']))