Zuul: Update jobs to ignore docs changes

This PS updates the multinode jobs to not run when changes only
effect the documentation.

Change-Id: I38027783a68d45fa0251c27c63b80fd6b56b4013

.zuul.yaml

@@ -20,8 +20,16 @@
             voting: true
         - openstack-helm-legacy-ubuntu-vm-ovs-radosgw:
             voting: false
+            irrelevant-files:
+              - ^.*\.rst$
+              - ^doc/.*$
+              - ^releasenotes/.*$
         - openstack-helm-legacy-ubuntu-vm-lb-radosgw:
             voting: false
+            irrelevant-files:
+              - ^.*\.rst$
+              - ^doc/.*$
+              - ^releasenotes/.*$
     gate:
       jobs:
         - openstack-helm-linter