chore: revert test

Author: wjhsf

packages/@lwc/integration-karma/test/component/LightningElement/index.spec.js

@@ -81,7 +81,8 @@ it("[W-6981076] shouldn't throw when a component with an invalid child in unmoun
     expect(() => document.body.removeChild(elm)).not.toThrow();
 });
 
-it('should fail when the constructor returns something other than an instance of itself', () => {
+// TODO [W-17769475]: Restore this test when we can reliably detect Locker enabled
+xit('should fail when the constructor returns something other than an instance of itself', () => {
     expect(() => {
         createElement('x-returning-bad', { is: ReturningBad });
     }).toThrowError(