Set openvswitch job as non-voting

This plugin is dedicated to test future podified ovn setups,
setups working only with openvswitch aren't planned with podified.

The ovs job often fails in gates, we should not let it block merging for
important fixes as long as ovn job results are stable.

Change-Id: I6adf8e84c664cec43e8092834266554642da5b7f

zuul.d/master_jobs.yaml

@@ -448,6 +448,7 @@
     name: whitebox-neutron-tempest-plugin-openvswitch
     parent: whitebox-neutron-tempest-plugin-base-nested-switch
     pre-run: playbooks/preparations.yaml
+    voting: false
     timeout: 10800
     vars:
       configure_swap_size: 2048

zuul.d/project.yaml

@@ -6,7 +6,9 @@
         - whitebox-neutron-tempest-plugin-ovn
         - whitebox-neutron-tempest-plugin-ovn-single-thread
     gate:
-      jobs: *neutron_jobs
+      jobs:
+        - whitebox-neutron-tempest-plugin-ovn
+        - whitebox-neutron-tempest-plugin-ovn-single-thread
 
 - project:
     templates: