Add stable/xena jobs on master gate

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

This also removes the stable/train job as that is in EM
state now.

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

Change-Id: Ia1ecf95d269af2f6edbd562f31fb69c2cc884cf0
diff --git a/zuul.d/jobs.yaml b/zuul.d/jobs.yaml
index 77615e1..4b836ea 100644
--- a/zuul.d/jobs.yaml
+++ b/zuul.d/jobs.yaml
@@ -520,6 +520,11 @@
         USE_PYTHON3: False
 
 - job:
+    name: octavia-v2-dsvm-noop-api-stable-xena
+    parent: octavia-v2-dsvm-noop-api
+    override-checkout: stable/xena
+
+- job:
     name: octavia-v2-dsvm-noop-api-stable-wallaby
     parent: octavia-v2-dsvm-noop-api
     override-checkout: stable/wallaby
@@ -536,12 +541,6 @@
     override-checkout: stable/ussuri
 
 - job:
-    name: octavia-v2-dsvm-noop-api-stable-train
-    parent: octavia-v2-dsvm-noop-api
-    nodeset: octavia-single-node-ubuntu-bionic
-    override-checkout: stable/train
-
-- job:
     name: octavia-v2-dsvm-scenario
     parent: octavia-dsvm-live-base
     vars:
@@ -596,6 +595,11 @@
         override-checkout: 2.30.0
 
 - job:
+    name: octavia-v2-dsvm-scenario-stable-xena
+    parent: octavia-v2-dsvm-scenario
+    override-checkout: stable/xena
+
+- job:
     name: octavia-v2-dsvm-scenario-stable-wallaby
     parent: octavia-v2-dsvm-scenario
     override-checkout: stable/wallaby
@@ -610,12 +614,6 @@
     nodeset: octavia-single-node-ubuntu-bionic
     override-checkout: stable/ussuri
 
-- job:
-    name: octavia-v2-dsvm-scenario-stable-train
-    parent: octavia-v2-dsvm-scenario
-    nodeset: octavia-single-node-ubuntu-bionic
-    override-checkout: stable/train
-
 # Legacy jobs for the transition to the act-stdby two node jobs
 - job:
     name: octavia-v2-dsvm-scenario-two-node
@@ -742,6 +740,11 @@
       - ^octavia_tempest_plugin/tests/(?!barbican_scenario/|\w+\.py).*
 
 - job:
+    name: octavia-v2-dsvm-tls-barbican-stable-xena
+    parent: octavia-v2-dsvm-tls-barbican
+    override-checkout: stable/xena
+
+- job:
     name: octavia-v2-dsvm-tls-barbican-stable-wallaby
     parent: octavia-v2-dsvm-tls-barbican
     override-checkout: stable/wallaby
@@ -801,6 +804,11 @@
         override-checkout: 2.30.0
 
 - job:
+    name: octavia-v2-dsvm-spare-pool-stable-xena
+    parent: octavia-v2-dsvm-spare-pool
+    override-checkout: stable/xena
+
+- job:
     name: octavia-v2-dsvm-spare-pool-stable-wallaby
     parent: octavia-v2-dsvm-spare-pool
     override-checkout: stable/wallaby
@@ -817,12 +825,6 @@
     override-checkout: stable/ussuri
 
 - job:
-    name: octavia-v2-dsvm-spare-pool-stable-train
-    parent: octavia-v2-dsvm-spare-pool
-    nodeset: octavia-single-node-ubuntu-bionic
-    override-checkout: stable/train
-
-- job:
     name: octavia-v2-dsvm-cinder-amphora
     parent: octavia-v2-dsvm-scenario
     required-projects:
@@ -952,6 +954,11 @@
       tox_envlist: all
 
 - job:
+    name: octavia-v2-act-stdby-dsvm-scenario-stable-xena
+    parent: octavia-v2-act-stdby-dsvm-scenario
+    override-checkout: stable/xena
+
+- job:
     name: octavia-v2-act-stdby-dsvm-scenario-stable-wallaby
     parent: octavia-v2-act-stdby-dsvm-scenario
     override-checkout: stable/wallaby
@@ -967,12 +974,6 @@
     nodeset: octavia-single-node-ubuntu-bionic
     override-checkout: stable/ussuri
 
-- job:
-    name: octavia-v2-act-stdby-dsvm-scenario-stable-train
-    parent: octavia-v2-act-stdby-dsvm-scenario
-    nodeset: octavia-single-node-ubuntu-bionic
-    override-checkout: stable/train
-
 ######### Third party jobs ##########
 
 - job: