Issue 5957 - Get the unit tests passing again

qunit/tests/prefs.js

 "use strict";
 
 {
   const {Prefs} = require("prefs");
 
-  module("Preferences", {
+  QUnit.module("Preferences", {
     setup()
     {
       this._pbackup = Object.create(null);
       for (let pref in Prefs)
       {
         let value = Prefs[pref];
         this._pbackup[pref] = value;
       }
       Prefs.enabled = true;
     },
@@ skipping 136 matching lines @@
     delete Prefs.notificationdata.foo;
     delete Prefs.notificationdata.bar;
     Prefs.notificationdata = JSON.parse(JSON.stringify(Prefs.notificationdata));
     deepEqual(
       Prefs.notificationdata, {},
       "Prefs object returns the correct value after setting pref to " +
       "default value"
     );
   });
 }