Merge branch 'mdangelo/523967-update-set_parent-work-item-quick-action-to-fail-gracefully-when-parent-is-invalid' into 'master' 

Update /set_parent work item quick action to fail gracefully when parent is invalid

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/183938



Merged-by: Roy Zwambag <rzwambag@gitlab.com>
Approved-by: Arpit Gogia <12347103-arpitgogia@users.noreply.gitlab.com>
Approved-by: Roy Zwambag <rzwambag@gitlab.com>
Co-authored-by: Matt D'Angelo <mdangelo@gitlab.com>