### 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 (!is_inside_tree() || is_input_disabled()) {
		return;
	}
	if (gui.subwindow_over) {
		gui.subwindow_over->_mouse_leave_viewport();
		gui.subwindow_over = nullptr;
	} else if (gui.mouse_over) {
		_drop_mouse_over();
	}
	notification(NOTIFICATION_VP_MOUSE_EXIT);
}
void Viewport::_drop_mouse_over() {
	_gui_cancel_tooltip();
	SubViewportContainer *c = Object::cast_to<SubViewportContainer>(gui.mouse_over);
	if (c) {
		for (int i = 0; i < c->get_child_count(); i++) {
			SubViewport *v = Object::cast_to<SubViewport>(c->get_child(i));
			if (!v) {
				continue;
			}
			v->_mouse_leave_viewport();
		}
	}
	if (gui.mouse_over->is_inside_tree()) {
		gui.mouse_over->notification(Control::NOTIFICATION_MOUSE_EXIT);
	}
	gui.mouse_over = nullptr;
}
void Viewport::push_input(const Ref<InputEvent> &p_event, bool p_local_coords) {