**Description**

Don't mark dag as `failed` when `UNSTABLE` status received from Jenkins.
It can be done by adding `allow_unstable: bool` or `success_status_values: list` parameter to `JenkinsJobTriggerOperator.__init__`. For now `SUCCESS` status is hardcoded, any other lead to fail.

**Use case / motivation**

I want to restart a job (`retries` parameter) only if I get `FAILED` status. `UNSTABLE` is okay for me and it's no need to restart.

**Are you willing to submit a PR?**

Yes

**Related Issues**

No

tests/providers/jenkins/operators/test_jenkins_job_trigger.py
(
                "dict params",
                {'a_param': 'blip', 'another_param': '42'},
            ),
            (
                "string params",
                '{"second_param": "beep", "third_param": "153"}',
            ),
            (
                "list params",
                ['final_one', 'bop', 'real_final', 'eggs'],
            ),
        ]
    )
    def test_execute_job_polling_loop(self, _, parameters):
        jenkins_mock = Mock(spec=jenkins.Jenkins, auth='secret')
        jenkins_mock.get_job_info.return_value = {'nextBuildNumber': '1'}
        jenkins_mock.get_build_info.side_effect = [
            {'result': None},
            {'result': 'SUCCESS', 'url': 'http://aaa.fake-url.com/congratulation/its-a-job'},
        ]
        jenkins_mock.build_job_url.return_value = 'http://www.jenkins.url/somewhere/in/the/universe'
        hook_mock = Mock(spec=JenkinsHook)
        hook_mock.get_jenkins_server.return_value = jenkins_mock
        with patch.object(JenkinsJobTriggerOperator, "get_hook") as get_hook_mocked, patch(
            'airflow.providers.jenkins.operators.jenkins_job_trigger.jenkins_request_with_headers'
        ) as mock_make_request:
            mock_make_request.side_effect = [
                {'body': '', 'headers': {'Location': 'http://what-a-strange.url/18'}},
                {'body': '{"executable":{"number":"1"}}', 'headers': {}},