Description:
Detailed description of the issue:

• What I did: Opened a dropdown menu in the frontend navigation.
• When it occurs: Every time a dropdown is opened and the user clicks outside the menu area.
  The JavaScript console reports an error from menu-metismenu.min.js.

Steps to reproduce:

1. Install Joomla and use the default Cassiopeia template.
2. Open the frontend.
3. Click a menu item that expands a dropdown.
4. Click anywhere outside the menu.
5. The dropdown remains open and the JavaScript console shows:
   menu-metismenu.min.js?04147a:7
   Uncaught TypeError: e.addEventListener is not a function

Expected behaviour:
The dropdown menu should collapse when clicking outside the menu area.

Actual behaviour:
The dropdown remains open, and the console shows:
Uncaught TypeError: e.addEventListener is not a function

Environment:

• Joomla version: 5.4 1, 6.0.1
• PHP version: 8.3
• Database: MySQL 8.4.3
• Browser: Chrome 142.0.7444.176

Additional information / attachments: