any blender version
Short description of error
Its not possible to right click on a menu and add a shortcut to it, you have to know the bl_idname of that menu and its not exposed by hovering the mouse on it, besides all blender versions have been with this problem, it can be considered a bug,
Exact steps for others to reproduce the error
Right click on a button and click change shortcut, It works!
Now Right click on a menu, no option appears.