message: Refactor `hide-disable-milestone-sorter` to use `selector-observer`
diff: -import select from 'select-dom';
  +import onetime from 'onetime';
  +import {observe} from 'selector-observer';
  import * as pageDetect from 'github-url-detection';
  import features from '.';
  -import observeElement from '../helpers/simplified-element-observer';
  function init(): void {
  - for (const icon of select.all('[aria-label="You do not have permission to edit this milestone."]')) {
  + observe('[aria-label="You do not have permission to edit this milestone."]', {
  + add(icon) {
  icon.parentElement!.remove();
  }
  + });
  }
  void features.add({
  @@ -18,11 +20,5 @@ void features.add({
  include: [
  pageDetect.isMilestone
  ],
  - exclude: [
  - // Issues container doesn't exist for milestones without (open) issues
  - () => !select.exists('.js-milestone-issues-container')
  - ],
  - init() {
  - observeElement('.js-milestone-issues-container', init);
  - }
  + init: onetime(init)
  });
  