Revert "Remove os_congress gating"
Revert "Remove os_congress gating"

We needed to remove gating for the deprecation process to remove
repository content. Once it's done we revert change to make CI work for
the stable branches.

Depends-On: https://review.opendev.org/742520
Change-Id: Ifd95291f7559be684cdea8312ff24778b67de077

openstack-infra/project-config,openstack-infra/project-config