Merge branch '298541-train-object-followups' into 'master'

Clean up MergeTrains::Train specs

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/125765



Merged-by: Mario Celi <mcelicalderon@gitlab.com>
Approved-by: Mario Celi <mcelicalderon@gitlab.com>
Approved-by: Hordur Freyr Yngvason <hfyngvason@gitlab.com>
Reviewed-by: Hordur Freyr Yngvason <hfyngvason@gitlab.com>
Co-authored-by: drew <dscimino@gmail.com>