### 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.
SignalWatcher *signal_watcher = nullptr;
	PhysicsServer3D *physics_server_3d = nullptr;
	PhysicsServer2D *physics_server_2d = nullptr;
	NavigationServer3D *navigation_server_3d = nullptr;
	NavigationServer2D *navigation_server_2d = nullptr;
	ThemeDB *theme_db = nullptr;
	void test_case_start(const doctest::TestCaseData &p_in) override {
		reinitialize();
		String name = String(p_in.m_name);
		String suite_name = String(p_in.m_test_suite);
		if (name.find("[SceneTree]") != -1) {
			memnew(MessageQueue);
			memnew(Input);
			Input::get_singleton()->set_use_accumulated_input(false);
			Error err = OK;
			OS::get_singleton()->set_has_server_feature_callback(nullptr);
			for (int i = 0; i < DisplayServer::get_create_function_count(); i++) {
				if (String("mock") == DisplayServer::get_create_function_name(i)) {
					DisplayServer::create(i, "", DisplayServer::WindowMode::WINDOW_MODE_MINIMIZED, DisplayServer::VSyncMode::VSYNC_ENABLED, 0, nullptr, Vector2i(0, 0), DisplayServer::SCREEN_PRIMARY, err);
					break;
				}
			}
			memnew(RenderingServerDefault());
			RenderingServerDefault::get_singleton()->init();
			RenderingServerDefault::get_singleton()->set_render_loop_enabled(false);
			physics_server_3d = PhysicsServer3DManager::get_singleton()->new_default_server();
			physics_server_3d->init();