Merge branch 'morefice/remove-memoization' into 'master'

Remove memoization for existing_sequence

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/146027



Merged-by: Marius Bobin <mbobin@gitlab.com>
Approved-by: Marius Bobin <mbobin@gitlab.com>
Co-authored-by: Maxime Orefice <morefice@gitlab.com>