vexxhost: load openstack/tempest jobs

It seems that openstack/tempest has a bunch of tempest-full-py3
jobs which need to be loaded to use the devstack jobs successfully.

Change-Id: I7cba84f844c906e773c3e9a96425c3c5ad108d7d

zuul/main.yaml

@@ -1523,6 +1523,7 @@
           - include: [job, secret, nodeset]
             projects:
               - openstack/devstack
+              - openstack/tempest
           # Include some projects without config for use in
           # required-projects
           - include: []
@@ -1535,7 +1536,6 @@
               - openstack/placement
               - openstack/requirements
               - openstack/swift
-              - openstack/tempest
 
 - tenant:
     name: zuul