Update stable branches jobs on master gate

we have stable/xena and stable/yoga also present
and supported so we should add their job on master
gate to keep branchless tempest plugins compatible
to stable branch.

This also removes the old EM stable branches which are
train, ussuri, and victoria jobs.

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

Change-Id: I3181e8a321aa36d06d00b0e96c2a7733a438aea3
diff --git a/.zuul.yaml b/.zuul.yaml
index ba6fc8c..a7de641 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -44,10 +44,9 @@
         - keystone-dsvm-py3-functional-federation-ubuntu-focal:
             voting: false
         - keystone-dsvm-py3-functional-federation-ubuntu-focal-k2k
+        - keystone-dsvm-py3-functional-yoga
+        - keystone-dsvm-py3-functional-xena
         - keystone-dsvm-py3-functional-wallaby
-        - keystone-dsvm-py3-functional-victoria
-        - keystone-dsvm-py3-functional-ussuri
-        - keystone-dsvm-py3-functional-train
         - keystone-protection-functional
     gate:
       jobs:
@@ -56,23 +55,16 @@
         - keystone-protection-functional
 
 - job:
+    name: keystone-dsvm-py3-functional-yoga
+    parent: keystone-dsvm-py3-functional
+    override-checkout: stable/yoga
+
+- job:
+    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
-
-- job:
-    name: keystone-dsvm-py3-functional-victoria
-    parent: keystone-dsvm-py3-functional
-    override-checkout: stable/victoria
-
-- job:
-    name: keystone-dsvm-py3-functional-ussuri
-    parent: keystone-dsvm-py3-functional
-    nodeset: openstack-single-node-bionic
-    override-checkout: stable/ussuri
-
-- job:
-    name: keystone-dsvm-py3-functional-train
-    parent: keystone-dsvm-py3-functional
-    nodeset: openstack-single-node-bionic
-    override-checkout: stable/train