This job only publishes part of the directory and needs to keep old content
around. Thus, add a new promote playbook that uses the
upload-afs-synchronize rule to not delete old content like the normal
playbook in the parent does.
Change-Id: I13f9faf698ec459f1d7cd7a950172d836b470a4c
The project-config tox publication jobs do the same thing. Follow the
same pattern and get rid of the specific playbook.
Change-Id: I42264e8dbd26d65dd354476bcdc7342ea2402b49