Update test/parallel/test-duplex-error.js

Co-authored-by: Luigi Pinca <luigipinca@gmail.com>

Author: aelhor

test/parallel/test-duplex-error.js

@@ -20,8 +20,3 @@ sideB.resume();
 
 sideB.destroy(new Error('Simulated error'));
 
-// Wrap the callback in common.mustCall()
-setImmediate(common.mustCall(() => {
-  assert.strictEqual(sideAErrorReceived, true);
-  assert.strictEqual(sideBErrorReceived, true);
-}));