`devops::release` issues without a category label

Attention @ogolowinski and @jlenny, The following issues have been identified in the devops::release stage that do not have a category label. These should be applied with urgency so that important issues are not being lost track of.

• #13631 (closed) Add link to pipeline type documentation in the merge request page UX, ~"devops::release", ~"devops::release::merge trains"
• #12145 (closed) (confidential) ~"(confidential)"