Merge branch '452365-refactor-uniq' into 'master'

Refactor achievements app to leverage uniqBy

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/148275



Merged-by: Miranda Fluharty <mfluharty@gitlab.com>
Approved-by: Rudy Crespo <rcrespo@gitlab.com>
Approved-by: Miranda Fluharty <mfluharty@gitlab.com>
Reviewed-by: Rudy Crespo <rcrespo@gitlab.com>
Co-authored-by: Rudy Crespo <rcrespo@gitlab.com>
Co-authored-by: Lee Tickett <ltickett@gitlab.com>