toggling locales does not take effect

[stopfstedt]

after upgrading to version 9.0.1, toggling the locale does not seem to cause a re-computation in the getters of my glimmer components that use the moment service.

example component and corresponding template:

import Component from '@glimmer/component';
import { action } from '@ember/object';
import { inject as service } from '@ember/service';

export default class MyComponent extends Component {
  @service moment;

  /**
   * the first day of the this week.
   * is locale dependent, e.g. with "en" locale that value would be "Sunday"
   * but with "es" locale it would be "lunes" (Monday)
   */
  get firstDayOfWeek() {
    return this.moment.moment().startOf('week').format('dddd');
  }

  @action
  changeLocale() {
    this.moment.setLocale('es');
  }
}

{{this.firstDayOfWeek}}

<button type="button" {{on "click" this.changeLocale}}>Change Locale</button>

i would expect that once i change the locale (invoking the changeLocale() action via a button click or the likes), that "lunes" would be returned from the getter, but it doesn't - it still gives me "Sunday".

this appears to be a regression, version 8 was working as expected.