Debian 11 uses ntfables, not iptables (like RHEL 8)

[Routhinator]

The firewall checks currently require that iptables be installed to pass, but much like the RHEL 8 STIG expectations, Debian 11 is a systemd system that leverages nftables under the hood, and these checks should be looking for nftables configuration on Debian 11+, not iptables.

[Routhinator]

https://www.stigqter.com/stigs/SV-230525r627750_rule.html