services/design: Remove obsolete toggle() method

Author: Turbo87

app/services/design.js

@@ -1,9 +1,6 @@
-import { action } from '@ember/object';
 import Service, { inject as service } from '@ember/service';
 import { tracked } from '@glimmer/tracking';
 
-import window from 'ember-window-mock';
-
 import config from '../config/environment';
 import * as localStorage from '../utils/local-storage';
 
@@ -13,16 +10,6 @@ export default class DesignService extends Service {
   @tracked useNewDesign = !this.fastboot.isFastBoot && localStorage.getItem('use-new-design') === 'true';
   @tracked showToggleButton = config.environment === 'development' || config.environment === 'test';
 
-  constructor() {
-    super(...arguments);
-    window.toggleDesign = () => this.toggle();
-  }
-
-  @action
-  toggle() {
-    this.setNewDesign(!this.useNewDesign);
-  }
-
   setNewDesign(value) {
     this.useNewDesign = value;
     localStorage.setItem('use-new-design', String(this.useNewDesign));