### 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.
switch (p_event) {
		case DisplayServer::WINDOW_EVENT_MOUSE_ENTER: {
			Window *root = get_tree()->get_root();
			if (root->gui.windowmanager_window_over) {
#ifdef DEV_ENABLED
				WARN_PRINT_ONCE("Entering a window while a window is hovered should never happen in DisplayServer.");
#endif 
				root->gui.windowmanager_window_over->_event_callback(DisplayServer::WINDOW_EVENT_MOUSE_EXIT);
			}
			_propagate_window_notification(this, NOTIFICATION_WM_MOUSE_ENTER);
			root->gui.windowmanager_window_over = this;
			notification(NOTIFICATION_VP_MOUSE_ENTER);
			if (DisplayServer::get_singleton()->has_feature(DisplayServer::FEATURE_CURSOR_SHAPE)) {
				DisplayServer::get_singleton()->cursor_set_shape(DisplayServer::CURSOR_ARROW); 
			}
		} break;
		case DisplayServer::WINDOW_EVENT_MOUSE_EXIT: {
			Window *root = get_tree()->get_root();
			if (!root->gui.windowmanager_window_over) {
#ifdef DEV_ENABLED
				WARN_PRINT_ONCE("Exiting a window while no window is hovered should never happen in DisplayServer.");
#endif 
				return;
			}
			root->gui.windowmanager_window_over->_mouse_leave_viewport();
			root->gui.windowmanager_window_over = nullptr;
			_propagate_window_notification(this, NOTIFICATION_WM_MOUSE_EXIT);
		} break;
		case DisplayServer::WINDOW_EVENT_FOCUS_IN: {
			focused = true;