### 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.
case NOTIFICATION_EXIT_TREE: {
			if (transient) {
				_clear_transient();
			}
			if (!is_embedded() && window_id != DisplayServer::INVALID_WINDOW_ID) {
				if (window_id == DisplayServer::MAIN_WINDOW_ID) {
					RS::get_singleton()->viewport_set_update_mode(get_viewport_rid(), RS::VIEWPORT_UPDATE_DISABLED);
					_update_window_callbacks();
				} else {
					_clear_window();
				}
			} else {
				if (embedder) {
					embedder->_sub_window_remove(this);
					embedder = nullptr;
					RS::get_singleton()->viewport_set_update_mode(get_viewport_rid(), RS::VIEWPORT_UPDATE_DISABLED);
				}
				_update_viewport_size(); 
			}
			RS::get_singleton()->viewport_set_active(get_viewport_rid(), false);
		} break;
		case NOTIFICATION_VP_MOUSE_ENTER: {
			emit_signal(SceneStringNames::get_singleton()->mouse_entered);
		} break;
		case NOTIFICATION_VP_MOUSE_EXIT: {
			emit_signal(SceneStringNames::get_singleton()->mouse_exited);
		} break;
	}
}
void Window::set_content_scale_size(const Size2i &p_size) {