message: Ensure the dropdown loaded in `git-checkout-pr`
diff: import React from 'dom-chef';
  import select from 'select-dom';
  import delegate from 'delegate-it';
  +import oneMutation from 'one-mutation';
  import {ClippyIcon} from '@primer/octicons-react';
  import * as pageDetect from 'github-url-detection';
  @@ -63,8 +64,12 @@ function checkoutOption(remote?: string, remoteType?: 'HTTPS' | 'SSH'): JSX.Elem
  );
  }
  -function handleMenuOpening({delegateTarget: dropdown}: delegate.Event): void {
  +async function handleMenuOpening({delegateTarget: dropdown}: delegate.Event): Promise<void> {
  dropdown.classList.add('rgh-git-checkout'); // Mark this as processed
  + if (select.exists('.SelectMenu-loading', dropdown)) { // The dropdown may still be loading
  + await oneMutation(dropdown, {childList: true, subtree: true});
  + }
  +
  const tabContainer = select('[action="/users/checkout-preference"]', dropdown)!.closest<HTMLElement>('tab-container')!;
  tabContainer.style.minWidth = '370px';
  select('.UnderlineNav-body', tabContainer)!.append(
  