CI/CD: Cleanup unused test environments
    
    Fix https://pagure.io/waiverdb/issue/248
    
    This PR will cleanup all test environments that were created 1 hour ago
    before creating a new test environment.
    
    The following Java methods must be approved to allow the pipeline script
    to access the Java DateTime API. For more information about Jenkins
    In-process Script Approval, see
    <https://jenkins.io/doc/book/managing/script-approval/>.
    
    ```
    method java.text.DateFormat parse java.lang.String
    method java.text.DateFormat setTimeZone java.util.TimeZone
    method java.util.Date getTime
    ```