Deprecate GitLab Managed Nginx v1

The one-click install offers minimal value over a manual install:

helm install ingress-nginx/ingress-nginx

The current GMA offering:

• Is opaque, do users trust it enough to use it for production?
• Cannot upgrade
• Cannot customize

Proposal

1. Deprecate GitLab Managed Nginx, and remove in GitLab %14.0
2. As an nginx controller is need for out-of-the-box Auto DevOps, have the auto-devops chart install ingress-nginx.

POC

tkuah/minimal-ruby-app!4 (closed) (blocked)