fix deprecation test

Author: pzuraq

packages/ember-runtime/tests/system/core_object_test.js

@@ -6,17 +6,17 @@ import { moduleFor, AbstractTestCase, buildOwner } from 'internal-test-helpers';
 moduleFor(
   'Ember.CoreObject',
   class extends AbstractTestCase {
-    ['@test throws deprecation with new (one arg)'](assert) {
-      assert.throws(() => {
+    ['@test throws deprecation with new (one arg)']() {
+      expectDeprecation(() => {
         new CoreObject({
           firstName: 'Stef',
           lastName: 'Penner',
         });
       }, /using `new` with EmberObject has been deprecated/);
     }
 
-    ['@test throws deprecation with new (> 1 arg)'](assert) {
-      assert.throws(() => {
+    ['@test throws deprecation with new (> 1 arg)']() {
+      expectDeprecation(() => {
         new CoreObject(
           {
             firstName: 'Stef',