Merge branch 'cleanup-upgrade-docs' into 'master'

Cleanup upgrade docs

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/126048



Merged-by: Achilleas Pipinellis <axil@gitlab.com>
Reviewed-by: Achilleas Pipinellis <axil@gitlab.com>
Co-authored-by: Ben Bodenmiller <bbodenmiller@gmail.com>