Fix todo creation on epics when toggling tasks

When toggling task list items, todo creation should be skipped. This
makes it consistent with issues and merge requests.

ee/app/services/ee/todo_service.rb

@@ -27,7 +27,7 @@ module EE
     end
 
     def update_epic(epic, current_user, skip_users = [])
-      create_mention_todos(nil, epic, current_user, nil, skip_users)
+      update_issuable(epic, current_user, skip_users)
     end
 
     # When a merge train is aborted for some reason, we should:

ee/changelogs/unreleased/292481-fix-tasklist-todos-epics.yml

+---
+title: Fix todo creation on epics when toggling tasks
+merge_request: 50827
+author:
+type: fixed

ee/spec/services/todo_service_spec.rb

@@ -168,6 +168,16 @@ RSpec.describe TodoService do
 
           include_examples 'todos creation'
         end
+
+        context 'when toggling task list items' do
+          before do
+            epic.update(description: "- [x] Task 1\n- [x] Task 2 FYI: #{mentions}")
+          end
+
+          it 'does not create todos' do
+            expect { execute }.not_to change { Todo.count }
+          end
+        end
       end
 
       describe '#new_note' do