Helm Chart: Fix chart-testing, upgrade ingress to networking.k8s.io/v1beta1, set metrics-provider=none if metrics scraper is not enabled. (#5691)

* Helm Chart: set metrics-provider=none if metrics scraper is not enabled.

* Helm CI: fix chart-testing-action configuration.

* Helm Chart: Switch Ingress from extensions/v1beta1 to networking.k8s.io/v1beta1. Requires kubernetes >= 1.14.0.