CI: Use 2023.2 image for rabbitmq on ipv6 scenario

Currently RMQ 3.13 fails on ipv6 multinode scenario, use 3.12 from 2023.1
until [1] gets resolved.

[1]: https://github.com/rabbitmq/rabbitmq-server/issues/10728

Change-Id: If11710e99cf2e340e558d68e2071c1bb16825e55

tests/templates/globals-default.j2

@@ -265,3 +265,10 @@ kolla_admin_openrc_cacert: "{% raw %}{{ kolla_certificates_dir }}{% endraw %}/ca
 {% if scenario == "skyline" %}
 enable_skyline: "yes"
 {% endif %}
+
+{# Workaround for https://github.com/rabbitmq/rabbitmq-server/issues/10728 #}
+{% if address_family == 'ipv6' %}
+{% raw %}
+rabbitmq_tag: "2023.2-{{ kolla_base_distro }}-{{ kolla_base_distro_version }}{{ openstack_tag_suffix }}"
+{% endraw %}
+{% endif %}