Add some projects to zuul zuul tenant

This adds zuul-jobs (which is needed for roles and jobs); since it
does not contain its own project stanza, it won't be "active" in
the tenant yet, it will just be present for use in jobs.

It also moves zuul-sphinx which does manage its own jobs.  It is
a slow-moving repo so we can test some jobs on it before we move
the rest of the projects over.

Change-Id: I3c5db1a9f88abce3d92f10dbb1443a987e08648f

zuul/main.yaml

@@ -231,7 +231,6 @@
           - openstack-infra/zone-zuul-ci.org
           - openstack-infra/zuul
           - openstack-infra/zuul-preview
-          - openstack-infra/zuul-sphinx
           - openstack-infra/zuul-website
           - openstack-infra/zuul-website-media
           - openstack/adjutant
@@ -1606,3 +1605,6 @@
               include:
                 - job
                 - secret
+        untrusted-projects:
+          - openstack-infra/zuul-jobs
+          - openstack-infra/zuul-sphinx