promote images to registry.k8s.io and use these for deployments

[BenTheElder]

we should be operating from production storage, not staging

it's more secure, and more resistant to SaaS changes (like the GCR => AR transition) because we control the domain/endpoint

these images should be getting promoted

docs: https://github.com/kubernetes/k8s.io/tree/main/registry.k8s.io#managing-kubernetes-container-registries

/sig contributor-experience

deployments:
https://github.com/kubernetes/k8s.io/tree/main/apps/slack-infra

(also the samples in this repo should be updated)

[BenTheElder]

In the meantime, it is also a problem that these are being deployed by tag from a staging registry, these should be pinned by digest AND served from registry.k8s.io.

[BenTheElder]

/assign

[BenTheElder]

filed image promotion here kubernetes/k8s.io#6973