[eventlet-removal] Remove "logger" mechanism from ML2/OVN CI jobs

The "logger" mechanism is a testing class that is still calling
monkey_patch. This mechanism driver is not relevant nor neccessary
for the ML2/OVN CI jobs.

Change-Id: I539b202ca81f62f4ae26b5275fd6b245d2066fe7

lib/neutron_plugins/ovn_agent

@@ -161,8 +161,10 @@ fi
 
 # Defaults Overwrite
 # ------------------
-
-Q_ML2_PLUGIN_MECHANISM_DRIVERS=${Q_ML2_PLUGIN_MECHANISM_DRIVERS:-ovn,logger}
+# NOTE(ralonsoh): during the eventlet removal, the "logger" mech
+# driver has been removed from this list. Re-add it once the removal
+# is finished or the mech driver does not call monkey_patch().
+Q_ML2_PLUGIN_MECHANISM_DRIVERS=${Q_ML2_PLUGIN_MECHANISM_DRIVERS:-ovn}
 Q_ML2_PLUGIN_TYPE_DRIVERS=${Q_ML2_PLUGIN_TYPE_DRIVERS:-local,flat,vlan,geneve}
 Q_ML2_TENANT_NETWORK_TYPE=${Q_ML2_TENANT_NETWORK_TYPE:-"geneve"}
 Q_ML2_PLUGIN_GENEVE_TYPE_OPTIONS=${Q_ML2_PLUGIN_GENEVE_TYPE_OPTIONS:-"vni_ranges=1:65536"}