BREAKING CHANGE: Migrate kubernetes repos referenced in this repo to `k8s-workloads/gitlab-helmfiles`

This is for https://gitlab.com/gitlab-com/gl-infra/infrastructure/-/issues/9571

The kubernetes raw manifests under `generic-configs` as well as the Kubernetes
roles/clusterrolebindings in README.md have been migrated to

https://gitlab.com/gitlab-com/gl-infra/k8s-workloads/gitlab-helmfiles