Remove KDS v1

[lahabana]

What happened?

It's been default for 2 versions! Remove in 2.7 🥳

[lobkovilya]

When cleaning up make sure we're not depending on specific types anymore when syncing resources, i.e. ZoneIngress/ZoneEgress in ZoneTag func:

kuma/pkg/kds/util/resource.go

Lines 107 to 121 in 70aaf52

	func ZoneTag(r model.Resource) string {
	switch res := r.GetSpec().(type) {
	case *mesh_proto.Dataplane:
	if res.GetNetworking().GetGateway() != nil {
	return res.GetNetworking().GetGateway().GetTags()[mesh_proto.ZoneTag]
	}
	return res.GetNetworking().GetInbound()[0].GetTags()[mesh_proto.ZoneTag]
	case *mesh_proto.ZoneIngress:
	return res.GetZone()
	case *mesh_proto.ZoneEgress:
	return res.GetZone()
	default:
	return ""
	}
	}

Functions like GlobalProvidedFilter/ZoneProvidedFilter and GlobalSyncCallback/ZoneSyncCallback should depend only on KDSFlags

[Icarus9913]

on me