message: fix(ember): use `_backburner` if it exists
diff: @@ -2,6 +2,7 @@ import ApplicationInstance from '@ember/application/instance';
  import Ember from 'ember';
  import { run, _backburner, scheduleOnce } from '@ember/runloop';
  import * as Sentry from '@sentry/browser';
  +import { ExtendedBackburner } from "@sentry/ember/runloop";
  import { Span, Transaction, Integration } from '@sentry/types';
  import { EmberRunQueues } from '@ember/runloop/-private/types';
  import { getActiveTransaction } from '..';
  @@ -28,11 +29,19 @@ export function initialize(appInstance: ApplicationInstance): void {
  }
  }
  -function getBackburner() {
  +function getBackburner(): Pick<ExtendedBackburner, "on" | "off"> {
  + if (_backburner) {
  + return _backburner;
  + }
  +
  if (run.backburner) {
  return run.backburner;
  }
  - return _backburner;
  +
  + return {
  + on() {},
  + off() {}
  + }
  }
  function getTransitionInformation(transition: any, router: any) {
  