Merge branch '461413-add-checklist-count-to-work-item-description' into 'master'

Resolve "Add checklist count to work item description"

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/156589



Merged-by: Paul Slaughter <pslaughter@gitlab.com>
Approved-by: Nick Leonard <nleonard@gitlab.com>
Approved-by: Deepika Guliani <dguliani@gitlab.com>
Approved-by: Coung Ngo <cngo@gitlab.com>
Approved-by: Paul Slaughter <pslaughter@gitlab.com>
Co-authored-by: Fernanda Toledo <ftoledo@gitlab.com>