Issue relative position scope in group boards does not include projects in subgroups

While looking at the code in https://gitlab.com/gitlab-org/gitlab-ee/blob/master/ee/app/models/ee/issue.rb#L84

# Issue position on boards list should be relative to all group projects
def parent_ids
  return super unless has_group_boards?

  board_group.projects.select(:id)
end

I think projects here should be all_projects so that it includes projects in subgroups. In the group board we show issues from projects in subgroups so this should be the same.

This could cause bugs where issues get reordered in unexpected ways.