Stop running jobs for the release-tools repo
Stop running jobs for the release-tools repo

The openstack-infra/release-tools repository is being retired, as
the Release Management Team ceased using it months ago. As a first
step, stop testing new changes for it so that we can replace its
content with a retirement notice.

Change-Id: Ia94fe9fcbffe9a748694290f5cb91b8ca26237b8

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