Pin stable branch jobs (victoria to zed) nodeset to Ubuntu Focal (20.04)

In 2023.1 cycle. we are moving the default distro
version of Ubuntu to Jammy (22.04)[1] so we need to pin
the nodeset for stable branch job in master gate so that
they continue run on their supporting distro version which is
Ubuntu Focal from stable/victoria until stable/zed.

[1] https://governance.openstack.org/tc/goals/selected/migrate-ci-jobs-to-ubuntu-jammy.html

Change-Id: I2c060d618bbbeaff63d506ffb00bc01750c8fcf3
diff --git a/zuul.d/victoria_jobs.yaml b/zuul.d/victoria_jobs.yaml
index 7a92403..247c10f 100644
--- a/zuul.d/victoria_jobs.yaml
+++ b/zuul.d/victoria_jobs.yaml
@@ -1,6 +1,7 @@
 - job:
     name: neutron-tempest-plugin-api-victoria
     parent: neutron-tempest-plugin-base
+    nodeset: openstack-single-node-focal
     override-checkout: stable/victoria
     required-projects: &required-projects-victoria
       - openstack/neutron
@@ -137,6 +138,7 @@
 - job:
     name: neutron-tempest-plugin-scenario-openvswitch-victoria
     parent: neutron-tempest-plugin-openvswitch
+    nodeset: openstack-single-node-focal
     override-checkout: stable/victoria
     required-projects: *required-projects-victoria
     vars:
@@ -166,6 +168,7 @@
 - job:
     name: neutron-tempest-plugin-scenario-openvswitch-iptables_hybrid-victoria
     parent: neutron-tempest-plugin-openvswitch-iptables_hybrid
+    nodeset: openstack-single-node-focal
     override-checkout: stable/victoria
     required-projects: *required-projects-victoria
     vars:
@@ -195,6 +198,7 @@
 - job:
     name: neutron-tempest-plugin-scenario-linuxbridge-victoria
     parent: neutron-tempest-plugin-linuxbridge
+    nodeset: openstack-single-node-focal
     override-checkout: stable/victoria
     required-projects: *required-projects-victoria
     vars:
@@ -224,6 +228,7 @@
 - job:
     name: neutron-tempest-plugin-scenario-ovn-victoria
     parent: neutron-tempest-plugin-ovn
+    nodeset: openstack-single-node-focal
     override-checkout: stable/victoria
     required-projects: *required-projects-victoria
     vars:
@@ -250,6 +255,7 @@
 - job:
     name: neutron-tempest-plugin-dvr-multinode-scenario-victoria
     parent: neutron-tempest-plugin-dvr-multinode-scenario
+    nodeset: openstack-two-node-focal
     override-checkout: stable/victoria
     required-projects: *required-projects-victoria
     vars:
@@ -259,6 +265,7 @@
 - job:
     name: neutron-tempest-plugin-designate-scenario-victoria
     parent: neutron-tempest-plugin-designate-scenario
+    nodeset: openstack-single-node-focal
     override-checkout: stable/victoria
     required-projects:
       - openstack/neutron
@@ -281,6 +288,7 @@
 - job:
     name: neutron-tempest-plugin-sfc-victoria
     parent: neutron-tempest-plugin-sfc
+    nodeset: openstack-single-node-focal
     override-checkout: stable/victoria
     required-projects: *required-projects-victoria
     vars:
@@ -290,6 +298,7 @@
 - job:
     name: neutron-tempest-plugin-bgpvpn-bagpipe-victoria
     parent: neutron-tempest-plugin-bgpvpn-bagpipe
+    nodeset: openstack-single-node-focal
     override-checkout: stable/victoria
     required-projects: *required-projects-victoria
     vars:
@@ -299,6 +308,7 @@
 - job:
     name: neutron-tempest-plugin-dynamic-routing-victoria
     parent: neutron-tempest-plugin-dynamic-routing
+    nodeset: openstack-single-node-focal
     override-checkout: stable/victoria
     required-projects: *required-projects-victoria
     vars:
@@ -308,6 +318,7 @@
 - job:
     name: neutron-tempest-plugin-vpnaas-victoria
     parent: neutron-tempest-plugin-vpnaas
+    nodeset: openstack-single-node-focal
     override-checkout: stable/victoria
     required-projects: *required-projects-victoria
     vars: