feat: add new checks for debian12

systemd_timesyncd_is_enabled_and_running.sh	-> 2.3.2.2
rpcbind_is_disabled.sh				-> 2.1.12
ftp_client_not_installed.sh			-> 2.2.6
chrony_with_chrony_user.sh			-> 2.3.3.2
ipv6_is_enabled.sh				-> 3.1.1

tests/hardening/ipv6_is_enabled.sh

@@ -0,0 +1,11 @@
+# shellcheck shell=bash
+# run-shellcheck
+test_audit() {
+
+    describe Running on blank host
+    register_test retvalshouldbe 0
+    dismiss_count_for_test
+    # shellcheck disable=2154
+    run blank "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+}