Document OS deprecations for 12.0

Steve Xuerebrequested to merge
add-os-deprecations into master

What does this MR do?

Document OS deprecations for 12.0, context #3473 (comment 140015228)

  • Make sure the old link is not removed and has its contents replaced with a link to the new location.
  • Make sure internal links pointing to the document in question are not broken.
  • Search and replace any links referring to old docs in GitLab Runner's source code
Edited by Steve Xuereb

Merge request reports