Viewport2Din3D connect_scene_signal function arguments incorrect

[Malcolmnixon]

In the master branch the Viewport2Din3D connect_scene_signal function is written as follows:

# Connect a 2D scene signal
func connect_scene_signal(which, on, callback):
    if scene_node:
        scene_node.connect(which, on, callback)

This matches the Godot 3 signature for connect:
Error connect ( String signal, Object target, String method, Array binds=[ ], int flags=0 )
However it should be modified to match the Godot 4 signature for connect:
Error connect ( StringName signal, Callable callable, int flags=0 )

As such the connect_scene_signal function should be modified to something like:

# Connect a 2D scene signal
func connect_scene_signal(which : String, callback : Callable, flags : int = 0):
    if scene_node:
        scene_node.connect(which, callback, flags)