Set koll_build_args as empty dict to avoid build error

Author: seunghun1ee

etc/kayobe/kolla.yml

@@ -365,7 +365,7 @@ kolla_build_customizations_ubuntu: {}
 kolla_build_customizations: "{{ kolla_build_customizations_common | combine(kolla_build_customizations_rocky if kolla_base_distro == 'rocky' else kolla_build_customizations_ubuntu) }}"
 
 # Dict mapping Kolla Dockerfile ARG names to their values.
-#kolla_build_args:
+kolla_build_args: {}
 
 ###############################################################################
 # Kolla-ansible inventory configuration.