Run the tests on stable/victoria as well, remove stein

So that changes to this plugin (at least, most of them) don't break
victoria.

As stein moved to EM, remove its job according the common guidelines.

Change-Id: If4857a8beaa46b48c0f7d44ff707dd44425b530c

.zuul.yaml

@@ -9,9 +9,9 @@
             voting: false
         - cinder-tempest-plugin-lvm-tgt-barbican
         - cinder-tempest-plugin-cbak-ceph
+        - cinder-tempest-plugin-basic-victoria
         - cinder-tempest-plugin-basic-ussuri
         - cinder-tempest-plugin-basic-train
-        - cinder-tempest-plugin-basic-stein
     gate:
       jobs:
         - cinder-tempest-plugin-lvm-lio-barbican
@@ -136,6 +136,12 @@
       - ^doc/.*$
       - ^releasenotes/.*$
 
+- job:
+    name: cinder-tempest-plugin-basic-victoria
+    parent: cinder-tempest-plugin-basic
+    nodeset: openstack-single-node-focal
+    override-checkout: stable/victoria
+
 - job:
     name: cinder-tempest-plugin-basic-ussuri
     parent: cinder-tempest-plugin-basic
@@ -150,12 +156,3 @@
     vars:
       devstack_localrc:
         USE_PYTHON3: True
-
-- job:
-    name: cinder-tempest-plugin-basic-stein
-    parent: cinder-tempest-plugin-basic
-    nodeset: openstack-single-node-bionic
-    override-checkout: stable/stein
-    vars:
-      devstack_localrc:
-        USE_PYTHON3: True