Submariner OVNK + GlobalNet datapath tests broken on latest OVNK

[yboaron]

Submariner datapath tests with OVNK and GlobalNet are failing when deployed using recent OVNK sources. See this job run for details.

[yboaron]

When using nftables in Submariner, all datapath tests passed successfully. Starting with Submariner 0.22, nftables will be used by default.

When Submariner uses iptables, there's race condition between Submariner GlobalNet and OVN-K NAT. Currently, there’s no straightforward way to resolve this solely on the Submariner side, as it would require a mechanism to “tell” OVN-K to skip NAT for specific traffic.

Since nftables becomes the default starting in version 0.22, we can lower the priority of this issue and even consider moving it to backlog.