### 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 (co && co->can_process()) {
						new_collider = result.collider_id;
						if (!capture_object) {
							last_object = co;
							last_id = result.collider_id;
							if (co->get_capture_input_on_drag() && mb.is_valid() && mb->get_button_index() == MouseButton::LEFT && mb->is_pressed()) {
								physics_object_capture = last_id;
							}
						}
					}
					if (is_mouse && new_collider != physics_object_over) {
						if (physics_object_over.is_valid()) {
							CollisionObject3D *previous_co = Object::cast_to<CollisionObject3D>(ObjectDB::get_instance(physics_object_over));
							if (previous_co) {
								previous_co->_mouse_exit();
							}
						}
						if (new_collider.is_valid()) {
							DEV_ASSERT(co);
							co->_mouse_enter();
						}
						physics_object_over = new_collider;
					}
					if (capture_object) {
						_collision_object_3d_input_event(capture_object, camera_3d, ev, result.position, result.normal, result.shape);
					} else if (new_collider.is_valid()) {
						_collision_object_3d_input_event(co, camera_3d, ev, result.position, result.normal, result.shape);
					}
				}
				last_pos = pos;