Define new 'cloudkitty-tempest-full-ipv6-only' job in gate

As part of Train community goal 'Support IPv6-Only Deployments and Testing'[1],
Tempest has defined the base job 'devstack-tempest-ipv6' (adding
in Depends-On patch) which will deploy services on IPv6.

This commit adds the new job 'cloudkitty-tempest-full-ipv6-only'
run on gate which is derived from 'devstack-tempest-ipv6'.

Verification structure will be:
- 'devstack-IPv6' deploy the service on IPv6
- 'devstack-tempest-ipv6' run will verify the IPv6-only setting and listen address
- 'cloudkitty-tempest-full-ipv6-only' will run the tests.

Story: #2005477
Task: #35884

Depends-On: https://review.opendev.org/#/c/671231/

[1] https://governance.openstack.org/tc/goals/train/ipv6-support-and-testing.html

Change-Id: I214b410137e825b529f0bdc34fda74ed1df091ab

.zuul.yaml

@@ -3,18 +3,18 @@
     parent: devstack-tempest
     description: |
       Job testing cloudkitty installation on devstack and running tempest tests
-    required-projects:
+    required-projects: &base_required_projects
       - name: openstack/cloudkitty
       - name: openstack/cloudkitty-tempest-plugin
       - name: openstack/python-cloudkittyclient
-    roles:
+    roles: &base_roles
       - zuul: openstack-infra/devstack
     timeout: 5400
-    irrelevant-files:
+    irrelevant-files: &base_irrelevant_files
       - ^.*\.rst$
       - ^doc/.*$
       - ^releasenotes/.*$
-    vars:
+    vars: &base_vars
       devstack_plugins:
         cloudkitty: https://opendev.org/openstack/cloudkitty
         cloudkitty-tempest-plugin: https://opendev.org/openstack/cloudkitty-tempest-plugin
@@ -30,6 +30,17 @@
         CLOUDKITTY_FETCHER: keystone
         TEMPEST_PLUGINS: /opt/stack/cloudkitty-tempest-plugin
 
+- job:
+    name: cloudkitty-tempest-full-ipv6-only
+    parent: devstack-tempest-ipv6
+    description: |
+      Job testing cloudkitty installation on devstack on IPv6 and running tempest tests
+    required-projects: *base_required_projects
+    roles: *base_roles
+    timeout: 5400
+    irrelevant-files: *base_irrelevant_files
+    vars: *base_vars
+
 - job:
     name: cloudkitty-tempest-full-python3
     parent: cloudkitty-tempest-full
@@ -75,6 +86,7 @@
       jobs:
         - cloudkitty-tempest-full
         - cloudkitty-tempest-full-python3
+        - cloudkitty-tempest-full-ipv6-only
         - cloudkitty-tox-bandit:
             voting: false
     gate:
@@ -82,3 +94,4 @@
       jobs:
         - cloudkitty-tempest-full
         - cloudkitty-tempest-full-python3
+        - cloudkitty-tempest-full-ipv6-only