Fix jQuery preference order to prevent conflicts with third-party widgets

When other Django admin widgets (like PrettyJSONWidget, JSONEditor, etc.)
load their own jQuery, they overwrite the global `jQuery` variable. Since
django_select2.js prefers `jQuery` over `window.django.jQuery`, it ends up
using the newly loaded jQuery instance which doesn't have Select2 attached.

This causes "$element.select2 is not a function" errors on admin pages.

By preferring `window.django.jQuery` (Django's protected instance), we ensure
Select2 functionality works regardless of what other widgets do to the global
jQuery variable.

Author: marcelo-maldonado95

django_select2/static/django_select2/django_select2.js

@@ -5,8 +5,8 @@
   } else if (typeof module === 'object' && module.exports) {
     module.exports = factory(require('jquery'))
   } else {
-    // Browser globals
-    factory(jQuery || window.django.jQuery)
+    // Browser globals - prefer Django's jQuery to avoid conflicts
+    factory(window.django.jQuery || jQuery)
   }
 }(function ($) {
   'use strict'