**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
jenkins_mock = Mock(spec=jenkins.Jenkins, auth='secret', timeout=2)
        jenkins_mock.build_job_url.return_value = 'http://apache.org'
        with patch(
            'airflow.providers.jenkins.operators.jenkins_job_trigger.jenkins_request_with_headers'
        ) as mock_make_request:
            operator = JenkinsJobTriggerOperator(
                dag=None,
                task_id="build_job_test",
                job_name="a_job_on_jenkins",
                jenkins_connection_id="fake_jenkins_connection",
            )
            operator.build_job(jenkins_mock)
            mock_request = mock_make_request.call_args_list[0][0][1]
        assert mock_request.method == 'POST'
        assert mock_request.url == 'http://apache.org'