Remove version upgrade docs and link to Dedicated team docs
Remove version upgrade docs and link to Dedicated team docs.
Version upgrade docs were added to the Dedicated team documentation by https://gitlab.com/gitlab-com/gl-infra/gitlab-dedicated/team/-/merge_requests/775. In this MR we remove the docs from this project and link to the ones that were added by https://gitlab.com/gitlab-com/gl-infra/gitlab-dedicated/team/-/merge_requests/775.
Edited by Reuben Pereira