Merge branch 'remove_chengelog_duplicate' into 'master'

Remove a changelog item that is added to CE (to prevent duplicating)

See merge request gitlab-org/gitlab-ee!4086

changelogs/unreleased-ee/42025-fix-issue-api.yml

----
-title: "[API] Fix creating issue when assignee_id is empty"
-merge_request:
-author:
-type: fixed