Add topology.kubernetes.io/zone

[leszko]

failure-domain.beta.kubernetes.io/zone is deprecated, we need to use topology.kubernetes.io/zone instead.

https://kubernetes.io/docs/reference/kubernetes-api/labels-annotations-taints/

[bykrmci]

• label "failure-domain.beta.kubernetes.io/zone" should be maintained to grant backward compatibility with Kubernetes < 1.17 (and consequently Openshift < 4.4 )
• label "failure-domain.kubernetes.io/zone" should be replaced by the label "topology.kubernetes.io/zone" to grant compliancy with Kubernetes >= 1.17 (and consequently Openshift 4.4+)

[leszko]

Yeah, I think to be backward-compatible we'll keep failure-domain.beta.kubernetes.io/zone (and probably also failure-domain.kubernetes.io/zone, because we've seen some clusters using it).