Update stable jobs on master gate

As zed is released, we should add its job on master
gate to keep branchless tempest plugins compatible
to stable branch.

Also, removing the stable/wallaby job as that is in EM
state.

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

Change-Id: I28117a37a41ac76ba5561a285e417882c2d6a5a1
diff --git a/.zuul.yaml b/.zuul.yaml
index a7de641..b1910d0 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -44,9 +44,9 @@
         - keystone-dsvm-py3-functional-federation-ubuntu-focal:
             voting: false
         - keystone-dsvm-py3-functional-federation-ubuntu-focal-k2k
+        - keystone-dsvm-py3-functional-zed
         - keystone-dsvm-py3-functional-yoga
         - keystone-dsvm-py3-functional-xena
-        - keystone-dsvm-py3-functional-wallaby
         - keystone-protection-functional
     gate:
       jobs:
@@ -55,6 +55,12 @@
         - keystone-protection-functional
 
 - job:
+    name: keystone-dsvm-py3-functional-zed
+    parent: keystone-dsvm-py3-functional
+    nodeset: openstack-single-node-focal
+    override-checkout: stable/zed
+
+- job:
     name: keystone-dsvm-py3-functional-yoga
     parent: keystone-dsvm-py3-functional
     override-checkout: stable/yoga
@@ -63,8 +69,3 @@
     name: keystone-dsvm-py3-functional-xena
     parent: keystone-dsvm-py3-functional
     override-checkout: stable/xena
-
-- job:
-    name: keystone-dsvm-py3-functional-wallaby
-    parent: keystone-dsvm-py3-functional
-    override-checkout: stable/wallaby