pkg/k8s: ignore namespace events that do not change labels
pkg/k8s: ignore namespace events that do not change labels

As we can receive different type of namespace events, like difference in
the annotations. We can ignore all of these events unless the labels are
different.

Signed-off-by: André Martins <bc9800b9d52a24cce72a73dd528afed53f10e5fc@cilium.io>

tklauser/cilium,tklauser/cilium,michi-covalent/cilium,cilium/cilium,tklauser/cilium,cilium/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,cilium/cilium,tklauser/cilium,michi-covalent/cilium,michi-covalent/cilium