feat(alpine): revert 3.19 -> 3.18

[aauren]

@mrueg

Revert because of issue with iptables v1.8.10 no longer working with -C check.

Still testing this in a local cluster to make sure that the problem doesn't re-occur. Long term, this needs to be chased down with upstream netfilter, but for now this should at least help us get to a stable version of kube-router on the v2.x release line.

Fixes: #1676

[TPXP]

Thanks a lot for taking the time to investigate and finding the root cause 🙌

Some nodes of our clusters run Linux 6.2, and we saw some issues with iptables failing on these kernels.

E0522 07:41:48.172118 1 network_policy_controller.go:259] Aborting sync. Failed to sync network policy chains: %!v(MISSING)ipset v7.15: Kernel and userspace incompatible: settype hash:ip with revision 6 not supported by userspace.

I haven't thoroughly experimented with all versions so I can't say for sure which version of ipset is required - I think kube-router v2.x builds worked but, just to be sure, you may want to test your build against these kernels as well