Task lists - additional performance tweak
Some additional performance can be gained for large task lists in issues/MRs/epics by removing the calls to
todo_service.update_issue(issuable, current_user)
todo_service.update_merge_request(merge_request, current_user)
todo_service.update_epic(epic, current_user)
in the various handle_task_changes
methods. It checks to see if any tasks have been toggled (which causes a potentially large parsing of tasks) only to determine if a task has changed, and if it has, simply returns. Since we know a task has been changed, the call seems unnecessary.