Merge branch '430141-avoid-parent-item-duplicates' into 'master'

Avoid duplicate items in Epic widget

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/155993



Merged-by: Coung Ngo <cngo@gitlab.com>
Approved-by: Tomas Vik <tvik@gitlab.com>
Approved-by: Minahil Nichols <minahilnichols@gitlab.com>
Approved-by: Coung Ngo <cngo@gitlab.com>
Co-authored-by: Rajan Mistry <rmistry@gitlab.com>