CI: Stop using infra cache servers as registry

It stopped working with docker-ce >= 29.0.0 and has proven
to be problematic in the past

Change-Id: I9a3d8d3dd268b7bb098b8e87d22b11e4ef0c72e9
Signed-off-by: Michal Nasiadka <mnasiadka@gmail.com>

Author: mnasiadka

tests/templates/globals-default.j2

@@ -84,13 +84,6 @@ podman_registry_insecure: yes
 {% endif %}
 openstack_tag: "{{ build_image_tag }}"
 {% else %}
-# use the published images from a site mirror of quay.io
-docker_registry: "{{ zuul_site_mirror_fqdn }}:4447"
-docker_registry_insecure: no
-{% if container_engine == 'podman' %}
-podman_registry: "{{ zuul_site_mirror_fqdn }}:4447"
-podman_registry_insecure: no
-{% endif %}
 docker_namespace: openstack.kolla
 {% if docker_image_tag_suffix %}
 openstack_tag_suffix: "{{ docker_image_tag_suffix }}"