Support both IPv4/IPv6 universally in squid configuration

cesnet-central/playbooks/templates/etc/squid/conf.d/allcluster.conf

 {% for host in groups['ingress'] + groups['nfs'] + groups['worker'] + groups['gpu'] -%}
+{% if hostvars[host].ansible_default_ipv6.address is defined %}
 acl allcluster src {{ hostvars[host].ansible_default_ipv6.address }}
+{% endif %}
 {% endfor -%}
 {% for host in groups['ingress'] + groups['nfs'] + groups['worker'] + groups['gpu'] -%}
+{% if hostvars[host].ansible_default_ipv4.address is defined %}
 acl allcluster src {{ hostvars[host].ansible_default_ipv4.address }}
+{% endif %}
 {% endfor -%}
 http_access allow allcluster

staging/playbooks/templates/etc/squid/conf.d/allcluster.conf

-{% for host in groups['ingress'] + groups['nfs'] + groups['worker'] + groups['gpu'] -%}
-acl allcluster src {{ hostvars[host].ansible_default_ipv4.address }}
-{% endfor -%}
-http_access allow allcluster

staging/playbooks/templates/etc/squid/conf.d/allcluster.conf

+../../../../../../cesnet-central/playbooks/templates/etc/squid/conf.d/allcluster.conf
\ No newline at end of file