feat: include localhost blocking in postgresql unit

Author: staaldraad

ansible/files/postgresql_config/postgresql.service.j2

@@ -23,6 +23,7 @@ EnvironmentFile=-/etc/environment.d/postgresql.env
 LimitNOFILE=16384
 {% if supabase_internal is defined %}
 ReadOnlyPaths=/etc
+IPAddressDeny=localhost
 {% endif %}
 [Install]
 WantedBy=multi-user.target