chore: rm dead code

src/hooks/use-modal-handler.ts

-import { MutableRefObject, useRef } from "react";
-
-interface Handler {
-  open: () => void;
-  close: () => void;
-}
-
-export type ModalHandler = MutableRefObject<Handler>;
-
-const useModalHandler = (): ModalHandler => {
-  return useRef({ open: () => {}, close: () => {} });
-};
-
-export default useModalHandler;