Most widgets utilize a Focus widget in their build method to manage their focus nowadays, but EditableText still keeps track of its own FocusNode. Instead, we should add a Focus widget to EditableTextState's build method, pass the FocusNode into it, and remove the redundant code around managing the FocusNode.

• EditableText manually attaches its FocusNode here, when it could be handled by a Focus widget instead.
• Here is where InkWell sets up its Focus widget, as an example, even though it also allows a FocusNode to be passed in. All of our Material buttons use InkWell to handle their focus.