Set buster job to NV

Recent nova does not support libvirt version that is provided in
Debian Buster, so we setting job to not voting.

Change-Id: I2c0bcbcfe1f8b4bee60a6069e4b2417ad5f67cf6

zuul.d/jobs.yaml

@@ -127,6 +127,7 @@
     name: openstack-ansible-functional-debian-buster
     parent: openstack-ansible-functional
     nodeset: debian-buster
+    voting: false
 
 - job:
     name: openstack-ansible-functional-ubuntu-bionic

zuul.d/project-templates.yaml

@@ -20,8 +20,7 @@
     gate:
       jobs:
         - openstack-ansible-linters
-        - openstack-ansible-functional-debian-buster
-        - openstack-ansible-functional-ubuntu-bionic
+        - openstack-ansible-functional-ubuntu-focal
     experimental:
       jobs:
         - openstack-ansible-integrated-deploy-aio
@@ -30,10 +29,10 @@
     name: openstack-ansible-upgrade
     check:
       jobs:
-        - openstack-ansible-upgrade-ubuntu-bionic
+        - openstack-ansible-upgrade-ubuntu-focal
     gate:
       jobs:
-        - openstack-ansible-upgrade-ubuntu-bionic
+        - openstack-ansible-upgrade-ubuntu-focal
 
 - project-template:
     name: openstack-ansible-role-distro_install-jobs