### 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.
bool is_transient() const;
	void set_exclusive(bool p_exclusive);
	bool is_exclusive() const;
	void set_clamp_to_embedder(bool p_enable);
	bool is_clamped_to_embedder() const;
	void set_unparent_when_invisible(bool p_unparent);
	bool is_in_edited_scene_root() const;
	bool can_draw() const;
	void set_ime_active(bool p_active);
	void set_ime_position(const Point2i &p_pos);
	bool is_embedded() const;
	Viewport *get_embedder() const;
	void set_content_scale_size(const Size2i &p_size);
	Size2i get_content_scale_size() const;
	void set_content_scale_mode(ContentScaleMode p_mode);
	ContentScaleMode get_content_scale_mode() const;
	void set_content_scale_aspect(ContentScaleAspect p_aspect);
	ContentScaleAspect get_content_scale_aspect() const;
	void set_content_scale_stretch(ContentScaleStretch p_stretch);
	ContentScaleStretch get_content_scale_stretch() const;
	void set_content_scale_factor(real_t p_factor);
	real_t get_content_scale_factor() const;
	void set_use_font_oversampling(bool p_oversampling);
	bool is_using_font_oversampling() const;
	void set_mouse_passthrough_polygon(const Vector<Vector2> &p_region);
	Vector<Vector2> get_mouse_passthrough_polygon() const;
	void set_wrap_controls(bool p_enable);
	bool is_wrapping_controls() const;
	void child_controls_changed();
	Window *get_exclusive_child() const { return exclusive_child; };