Fix branch regex to cover unmaintained branches

Required to keep running jobs when branches are
renamed from stable to unmaintained.

yoga already transitioned to unmaintained. victoria,
wallaby and xena are in progress.

Related-Bug: #2056276
Change-Id: I12eac55c9864eeeed255f426c537b7e53e908521
diff --git a/zuul.d/stable-jobs.yaml b/zuul.d/stable-jobs.yaml
index 50ae841..501d2ec 100644
--- a/zuul.d/stable-jobs.yaml
+++ b/zuul.d/stable-jobs.yaml
@@ -97,7 +97,7 @@
       - stable/victoria
       - stable/wallaby
       - stable/xena
-      - stable/yoga
+      - unmaintained/yoga
       - stable/zed
     vars:
       devstack_localrc:
@@ -120,7 +120,7 @@
       - stable/victoria
       - stable/wallaby
       - stable/xena
-      - stable/yoga
+      - unmaintained/yoga
       - stable/zed
     vars:
       devstack_localrc:
@@ -168,7 +168,7 @@
     branches:
       - stable/wallaby
       - stable/xena
-      - stable/yoga
+      - unmaintained/yoga
     description: |
       This job runs integration tests for compute. This is
       subset of 'tempest-full-py3' job and run Nova, Neutron, Cinder (except backup tests)
@@ -187,7 +187,7 @@
     branches:
       - stable/wallaby
       - stable/xena
-      - stable/yoga
+      - unmaintained/yoga
     nodeset: devstack-single-node-centos-8-stream
     description: |
       Base integration test with Neutron networking and py36 running