Update Kubernetes client-go library to 0.21.1
What does this MR do?
Upgrades the k8s.io/client-go
library to newer version.
Why was this MR needed?
It's a requirement to move Runner to Go 1.16, as it's mentioned in #27776.
What's the best way to test this MR?
What are the relevant issue numbers?
Part of #27776 and #27568 (closed) in a wider scope
Edited by Tomasz Maczukin