This wasn't as clever as I thought it would be. Multiple inclusions are
considered errors. So, I added it back as part of the maven job. It's likely
that services would be including the build/maven.yml config anyway, or their
pipeline wouldn't build.

This should enable later parts of the pipeline to start as soon as their own
dependencies are satisfied, without waiting for the entire stage to complete.

This reverts commit 4ab7539e.