feat: add debian12 scripts

- iptables_loopback.sh 			-> 4.3.2.2
- iptables_rules_them_all.sh 		-> 4.3.2.4
- iptables_outbound_established.sh 	-> 4.3.2.3
- ip6tables_loopback.sh			-> 4.3.3.2
- ip6tables_outbound_established.sh	-> 4.3.3.3
- ip6tables_rules_them_all.sh		-> 4.3.3.4
- ip6tables_default_deny_policy.sh 	-> 4.3.3.1

tests/hardening/ipv6_is_enabled.sh

@@ -1,28 +1,10 @@
 # shellcheck shell=bash
 # run-shellcheck
-is_ipv6_enabled() {
-
-    CURRENT_IPV6_ENABLED=1
-    if sysctl net.ipv6 >/dev/null 2>&1; then
-        for iface in /proc/sys/net/ipv6/conf/*; do
-            ifname=$(basename "$iface")
-            if [ "$ifname" != "default" ] && [ "$ifname" != "all" ]; then
-                value=$(cat "$iface"/disable_ipv6)
-                # if only one interface has ipv6, this is enough to consider it enabled
-                if [ "$value" -eq 0 ]; then
-                    CURRENT_IPV6_ENABLED=0
-                    break
-                fi
-            fi
-        done
-    fi
-}
-
 test_audit() {
     # shellcheck disable=2154
     "${CIS_CHECKS_DIR}/${script}.sh" --create-config-files-only
 
-    is_ipv6_enabled
+    tests_is_ipv6_enabled
     if [ "$CURRENT_IPV6_ENABLED" -eq 0 ]; then
         describe prepare failing test
         # shellcheck disable=2154