### Body

We have several tests marked in the code base with `@pytest.mark.quarantined`
It means that the tests are flaky and if fail in CI it does not fail the build.
The goal is to fix the tests and make them stable.

This task is to gather all of them under the same issue instead of dedicated issue per test.

- [x] [TestImpersonation](https://github.com/apache/airflow/blob/bfcae349b88fd959e32bfacd027a5be976fe2132/tests/core/test_impersonation_tests.py#L117)
- [x] [TestImpersonationWithCustomPythonPath](https://github.com/apache/airflow/blob/bfcae349b88fd959e32bfacd027a5be976fe2132/tests/core/test_impersonation_tests.py#L181)
- [x] [test_exception_propagation](https://github.com/apache/airflow/blob/76f81cd4a7433b7eeddb863b2ae6ee59176cf816/tests/jobs/test_local_task_job.py#L772)
- [x] [test_localtaskjob_maintain_heart_rate](https://github.com/apache/airflow/blob/76f81cd4a7433b7eeddb863b2ae6ee59176cf816/tests/jobs/test_local_task_job.py#L402)
- [x] [test_exception_propagation](https://github.com/apache/airflow/blob/4d0fd8ef6adc35f683c7561f05688a65fd7451f4/tests/executors/test_celery_executor.py#L103)
- [x] [test_process_sigterm_works_with_retries](https://github.com/apache/airflow/blob/65010fda091242870a410c65478eae362899763b/tests/jobs/test_local_task_job.py#L770)


### Committer

- [X] I acknowledge that I am a maintainer/committer of the Apache Airflow project.
"""
        Test that ensures that mark_success in the UI doesn't cause
        the task to fail, and that the task exits
        """
        dag = get_test_dag("test_mark_state")
        dr = dag.create_dagrun(
            state=State.RUNNING,
            execution_date=DEFAULT_DATE,
            run_type=DagRunType.SCHEDULED,
            session=session,
        )
        task = dag.get_task(task_id="test_mark_success_no_kill")
        ti = dr.get_task_instance(task.task_id)
        ti.refresh_from_task(task)
        job1 = LocalTaskJob(task_instance=ti, ignore_ti_state=True)
        with timeout(30):
            job1.run()
        ti.refresh_from_db()
        assert State.SUCCESS == ti.state
        assert (
            "State of this instance has been externally set to success. Terminating instance." in caplog.text
        )
    def test_localtaskjob_double_trigger(self):