Expand the use of helmfile to other repositories

@ggillies has created an excellent PoC for the use of helmfile for the k8s-workloads/gitlab-com repo that we've adopted: delivery#655 (closed) and integrated it into our tooling. We have a few repos that this can benefit from. All of them located here: delivery#655 (closed) Take a close look at issue comment for details on where we currently stand on this work thus far: delivery#655 (comment 289832718)

Utilize this issue to consider and perform the work necessary to bring helmfile to the rest of these repositories.

For some, clean up may be required: https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/9295