After migration from old QE jenkins to new main-jenkins, GH repo polling appears to be broken as we're not getting automated builds when upstream code is changed.

Possible solutions:

• add GH project to .groovy files (as we had in old jenkins jobs)
• add manual checkouts of upstream projects w/ polling enabled (if this even works when using openstack images such that no poll logs persist between builds?)
• add crontab-based builds to trigger builds at 2h intervals, but don't create new containers if no changes commited to midstream (this should already be enabled for some jobs; need to verify this actually fires and check what happens)

Or if none of the above, could we...

• use GH action in upstream to trigger builds?
• store our own UPSTREAM_VERSION file in midstream, and use that as persistent poll log against which to compare changing SHAs