message: fix(core): remove deprecated wtfZoneSpec from NgZone
  Since `WTF` is deprecated and removed in v9 in this PR so
  in this PR, `WtfZoneSpec` is also removed from `NgZone`.
  PR Close
diff: @@ -130,10 +130,6 @@ export class NgZone {
  self._outer = self._inner = Zone.current;
  - if ((Zone as any)['wtfZoneSpec']) {
  - self._inner = self._inner.fork((Zone as any)['wtfZoneSpec']);
  - }
  -
  if ((Zone as any)['TaskTrackingZoneSpec']) {
  self._inner = self._inner.fork(new ((Zone as any)['TaskTrackingZoneSpec'] as any));
  }
  