JENKINS-51776 Restarting during saucelabs run now works

[timja]

https://issues.jenkins.io/browse/JENKINS-51776

Best to review #82 first

cc @alexh-sauce @sauce-jenkins-bot

Example pipeline I used for reproducing:

node {
    stage('Checkout') {
        git 'https://github.com/timja/demo-java.git'
    }
    
    stage('Build') {
        dir('on-boarding-modules/testng') {
            sh 'mvn compile'
        }
    }
    
    stage('Test') {
        dir('on-boarding-modules/testng') {
            sauce('my-credential-id') {
                sauceconnect(useGeneratedTunnelIdentifier: true, verboseLogging: true) {
                    sh 'mvn test'
                }
            }
        }
    }
}

The repo is a fork of https://github.com/saucelabs-training/demo-java changed to use the EU endpoint and to add a sleep to the test to make it easier to reproduce

[timja]

@sauce-jenkins-bot looks like your release failed, could you retry please