### 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.
if (p_node != this) {
		Window *w = Object::cast_to<Window>(p_node);
		if (w && (!w->is_inside_tree() || !w->is_embedded())) {
			return;
		}
		CanvasItem *ci = Object::cast_to<CanvasItem>(p_node);
		if (ci) {
			ci->queue_redraw();
		}
	}
	int cc = p_node->get_child_count();
	for (int i = 0; i < cc; i++) {
		_update_canvas_items(p_node->get_child(i));
	}
}
Ref<ViewportTexture> Viewport::get_texture() const {
	ERR_READ_THREAD_GUARD_V(Ref<ViewportTexture>());
	return default_texture;
}
void Viewport::set_positional_shadow_atlas_size(int p_size) {
	ERR_MAIN_THREAD_GUARD;
	positional_shadow_atlas_size = p_size;
	RS::get_singleton()->viewport_set_positional_shadow_atlas_size(viewport, p_size, positional_shadow_atlas_16_bits);
}
int Viewport::get_positional_shadow_atlas_size() const {