Merge branch 'docs-501103_adjust_user_doc_and_migration_guide_for_DS_with_SBOM' into 'master'

Adjust user documentation and migration guide for DS using SBOM

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/181557



Merged-by: Ryan Lehmann <rlehmann@gitlab.com>
Approved-by: Oscar Tovar <otovar@gitlab.com>
Reviewed-by: Ryan Lehmann <rlehmann@gitlab.com>
Co-authored-by: Olivier Gonzalez <ogonzalez@gitlab.com>