### 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.
class SceneTreeTimer;
class Viewport;
class Window;
class World2D;
class ViewportTexture : public Texture2D {
	GDCLASS(ViewportTexture, Texture2D);
	NodePath path;
	friend class Viewport;
	Viewport *vp = nullptr;
	bool vp_pending = false;
	bool vp_changed = false;
	void _setup_local_to_scene(const Node *p_loc_scene);
	mutable RID proxy_ph;
	mutable RID proxy;
protected:
	static void _bind_methods();
public:
	void set_viewport_path_in_scene(const NodePath &p_path);
	NodePath get_viewport_path_in_scene() const;
	virtual void setup_local_to_scene() override;
	virtual int get_width() const override;
	virtual int get_height() const override;
	virtual Size2 get_size() const override;
	virtual RID get_rid() const override;
	virtual bool has_alpha() const override;
	virtual Ref<Image> get_image() const override;
	ViewportTexture();
	~ViewportTexture();
};
class Viewport : public Node {