update nova-next and nova-ovs-hybrid-plug to disable linuxbridge

neutron now declares linuxbridge experimental and requires
it to be enabled by a new config option. We do not set
that in these jobs so the neutron server fails to load
since we enable the linux bridge mech driver.

we do not actully use linuxbridge in these jobs so this patch
just disables the mech driver.

Change-Id: I129a850c3327498d26d899c7709f5749622afdd8
Closes-Bug: #1980948

Author: SeanMooney

.zuul.yaml

@@ -135,7 +135,7 @@
       devstack_localrc:
         Q_AGENT: openvswitch
         Q_ML2_TENANT_NETWORK_TYPE: vxlan
-        Q_ML2_PLUGIN_MECHANISM_DRIVERS: openvswitch,linuxbridge
+        Q_ML2_PLUGIN_MECHANISM_DRIVERS: openvswitch
         ML2_L3_PLUGIN: router
       devstack_services:
         # Disable OVN services
@@ -162,7 +162,7 @@
         devstack_localrc:
           Q_AGENT: openvswitch
           Q_ML2_TENANT_NETWORK_TYPE: vxlan
-          Q_ML2_PLUGIN_MECHANISM_DRIVERS: openvswitch,linuxbridge
+          Q_ML2_PLUGIN_MECHANISM_DRIVERS: openvswitch
           ML2_L3_PLUGIN: router
         devstack_services:
           # Disable OVN services
@@ -391,7 +391,7 @@
       devstack_localrc:
         Q_AGENT: openvswitch
         Q_ML2_TENANT_NETWORK_TYPE: vxlan
-        Q_ML2_PLUGIN_MECHANISM_DRIVERS: openvswitch,linuxbridge
+        Q_ML2_PLUGIN_MECHANISM_DRIVERS: openvswitch
         ML2_L3_PLUGIN: router
         # Enable TLS between the noVNC proxy & compute nodes; this requires
         # the tls-proxy service to be enabled. Added in Queens.
@@ -430,7 +430,7 @@
         devstack_localrc:
           Q_AGENT: openvswitch
           Q_ML2_TENANT_NETWORK_TYPE: vxlan
-          Q_ML2_PLUGIN_MECHANISM_DRIVERS: openvswitch,linuxbridge
+          Q_ML2_PLUGIN_MECHANISM_DRIVERS: openvswitch
           ML2_L3_PLUGIN: router
           NOVA_CONSOLE_PROXY_COMPUTE_TLS: True
           FORCE_CONFIG_DRIVE: True