CI: Disable libvirt debug logs

Libvirt debug logs can grow very large, particularly on Ubuntu (we have
seen up to 1.1GB). Disable libvirt debug logging using variable
nova_libvirt_logging_debug which was added to Kolla Ansible during the
Wallaby cycle (see change I90bfd1b300ad3202ea4d139fda6d6beb44c5820f) and
backported to Victoria and Ussuri.

Change-Id: Ic047e80aa382148b009b1c03581b417d17ec2598

playbooks/kayobe-overcloud-base/globals.yml.j2

@@ -12,6 +12,9 @@ nova_compute_virt_type: qemu
 openstack_service_workers: "1"
 openstack_service_rpc_workers: "1"
 
+# Reduce size of libvirt logs when OpenStack debug logging is enabled
+nova_libvirt_logging_debug: False
+
 {% if tls_enabled %}
 # TLS
 kolla_copy_ca_into_containers: "yes"

playbooks/kayobe-overcloud-upgrade-base/globals.yml.j2

@@ -11,3 +11,6 @@ nova_compute_virt_type: qemu
 # processes to one per-service.
 openstack_service_workers: "1"
 openstack_service_rpc_workers: "1"
+
+# Reduce size of libvirt logs when OpenStack debug logging is enabled
+nova_libvirt_logging_debug: False