### Godot version

v4.1.1.stable.official [bd6af8e0e]

### System information

Godot v4.1.1.stable - Debian GNU/Linux trixie/sid trixie - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1060 (nvidia) - Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz (6 Threads)

### Issue description

`Area2D`s which extend beyond the bounds of the root viewport, eg. when using a `canvas_items` stretch mode, receive mouse input events even in the black bands letterboxing the game:

https://github.com/godotengine/godot/assets/441188/3beb962f-c1fa-4098-a375-f3d862013577


### Steps to reproduce

1. Set project stretch mode to either `canvas_items` or `viewport`
2. Have an `Area2D` whose `CollisionShape` extends beyond the bounds of the rendered region
3. Connect the `Area2D`'s `mouse_[entered|exited]` signal to something
4. Wave the mouse around in the black areas outside the rendered game

### Minimal reproduction project

Project used for video demo above:

[area2d-oob.zip](https://github.com/godotengine/godot/files/12207031/area2d-oob.zip)

This only demos `mouse_[entered|exited]`, but I first encountered this with the `Area2D.input_event` signal, where it received mouse clicks as well.
ERR_FAIL_NULL(p_control);
	ERR_FAIL_COND(p_control->is_inside_tree());
	ERR_FAIL_COND(p_control->get_parent() != nullptr);
	Control *drag_preview = _gui_get_drag_preview();
	if (drag_preview) {
		memdelete(drag_preview);
	}
	p_control->set_as_top_level(true);
	p_control->set_position(gui.last_mouse_pos);
	p_base->get_root_parent_control()->add_child(p_control); 
	p_control->move_to_front();
	gui.drag_preview_id = p_control->get_instance_id();
}
Control *Viewport::_gui_get_drag_preview() {
	if (gui.drag_preview_id.is_null()) {
		return nullptr;
	} else {
		Control *drag_preview = Object::cast_to<Control>(ObjectDB::get_instance(gui.drag_preview_id));
		if (!drag_preview) {
			ERR_PRINT("Don't free the control set as drag preview.");
			gui.drag_preview_id = ObjectID();
		}
		return drag_preview;
	}
}
void Viewport::_gui_remove_root_control(List<Control *>::Element *RI) {