test: fix lint error by removing unused common variable assignment

Remove variable assignment from common module require to fix ESLint
no-unused-vars error.

Author: Amemome

test/parallel/test-whatwg-events-add-event-listener-options-passive.js

@@ -1,6 +1,6 @@
 'use strict';
 
-const common = require('../common');
+require('../common');
 
 // Manually converted from https://github.com/web-platform-tests/wpt/blob/master/dom/events/AddEventListenerOptions-passive.html
 // in order to define the `document` ourselves