[Deprecation Alert] Stop supporting iptables on masquerade binding

[Alona Paz]

Hi all,

Kubevirt has been using nftables more than a year [1] by default.

Our e2e tests have not covered iptables for an even longer period (as the iptables binary was actually using nftables in the backend).

Therefore, we would like to declare iptables as deprecated and remove its code from the Kubevirt code base.

We pan to remove iptables completely in Kubevirt release v0.56.0.

It means that nodes with iptables only won't be able to run VMs with masquerade binding.

We are looking forward to hearing feedback and concerns regarding this depreciation.

[1] https://github.com/kubevirt/kubevirt/pull/5026

Thanks,

Alona.