https://developer.mozilla.org/zh-CN/docs/Web/API/EventTarget/removeEventListener

function handleChange() {
  // ...
}

// sub
window.cookieStore.addEventListener('change', handleChange);
// unsub
window.cookieStore.removeEventListener('change', handleChange);

or

const controller = new AbortController();

// sub
window.cookieStore.addEventListener('change', { signal: controller.signal });
// unsub
controller.abort();