Add stable/wallaby jobs on master gate

We have stable/wallaby released so we should add
their job on master gate to keep branchless tempest
plugins compatible to stable branch.

Ref: Tempest plugins guide for stable branch testing:
- https://docs.openstack.org/tempest/latest/stable_branch_testing_policy.html

Change-Id: I493f44fdc7b5d4093e19ca19153644c20517941f
diff --git a/.zuul.yaml b/.zuul.yaml
index 87f89f0..0ad6e1f 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -11,6 +11,7 @@
         - nova-ceph-multistore:
             voting: false
         - cinder-tempest-plugin-cbak-ceph
+        - cinder-tempest-plugin-basic-wallaby
         - cinder-tempest-plugin-basic-victoria
         - cinder-tempest-plugin-basic-ussuri
         - cinder-tempest-plugin-basic-train
@@ -21,6 +22,7 @@
         - cinder-tempest-plugin-cbak-ceph
     experimental:
       jobs:
+        - cinder-tempest-plugin-cbak-ceph-wallaby
         - cinder-tempest-plugin-cbak-ceph-victoria
         - cinder-tempest-plugin-cbak-ceph-ussuri
         - cinder-tempest-plugin-cbak-ceph-train
@@ -107,6 +109,12 @@
         c-bak: true
 
 - job:
+    name: cinder-tempest-plugin-cbak-ceph-wallaby
+    parent: cinder-tempest-plugin-cbak-ceph
+    nodeset: openstack-single-node-focal
+    override-checkout: stable/wallaby
+
+- job:
     name: cinder-tempest-plugin-cbak-ceph-victoria
     parent: cinder-tempest-plugin-cbak-ceph
     nodeset: openstack-single-node-focal
@@ -185,6 +193,12 @@
       - ^releasenotes/.*$
 
 - job:
+    name: cinder-tempest-plugin-basic-wallaby
+    parent: cinder-tempest-plugin-basic
+    nodeset: openstack-single-node-focal
+    override-checkout: stable/wallaby
+
+- job:
     name: cinder-tempest-plugin-basic-victoria
     parent: cinder-tempest-plugin-basic
     nodeset: openstack-single-node-focal