From the GitHub repository hosting request:

My immediate concern is about the plugin deps, which are best avoided in test harness artifacts due to technical difficulties with Maven. I think you could do without. For example, the Pipeline deps seem to support just a small number of utilities related to defining jobs, which could be inlined, or if necessary proposed for addition to the `tests` JARs of some `workflow-*` plugins. The `ssh-slaves` dep could perhaps be removed by simplifying how Dockerized agents are launched: do the equivalent of https://github.com/jenkinsci/docker-agent#usage using `SimpleCommandLauncher`, or use an inbound agent as in https://github.com/jenkinsci/workflow-cps-plugin/blob/d0a8f6a1c2631aecac324ba574a22d4a55425463/src/test/java/org/jenkinsci/plugins/workflow/cps/SerialFormTest.java#L79-L86.