### 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 subwindow_drag_close_inside = false;
		SubWindowResize subwindow_resize_mode;
		Rect2i subwindow_resize_from_rect;
		Vector<SubWindow> sub_windows; 
	} gui;
	DefaultCanvasItemTextureFilter default_canvas_item_texture_filter = DEFAULT_CANVAS_ITEM_TEXTURE_FILTER_LINEAR;
	DefaultCanvasItemTextureRepeat default_canvas_item_texture_repeat = DEFAULT_CANVAS_ITEM_TEXTURE_REPEAT_DISABLED;
	bool disable_input = false;
	bool _gui_call_input(Control *p_control, const Ref<InputEvent> &p_input);
	void _gui_call_notification(Control *p_control, int p_what);
	void _gui_sort_roots();
	Control *_gui_find_control_at_pos(CanvasItem *p_node, const Point2 &p_global, const Transform2D &p_xform);
	void _gui_input_event(Ref<InputEvent> p_event);
	void _perform_drop(Control *p_control = nullptr, Point2 p_pos = Point2());
	void _gui_cleanup_internal_state(Ref<InputEvent> p_event);
	void _push_unhandled_input_internal(const Ref<InputEvent> &p_event);
	Ref<InputEvent> _make_input_local(const Ref<InputEvent> &ev);
	friend class Control;
	List<Control *>::Element *_gui_add_root_control(Control *p_control);
	void _gui_remove_root_control(List<Control *>::Element *RI);
	String _gui_get_tooltip(Control *p_control, const Vector2 &p_pos, Control **r_tooltip_owner = nullptr);
	void _gui_cancel_tooltip();
	void _gui_show_tooltip();
	void _gui_remove_control(Control *p_control);
	void _gui_hide_control(Control *p_control);
	void _gui_force_drag(Control *p_base, const Variant &p_data, Control *p_control);
	void _gui_set_drag_preview(Control *p_base, Control *p_control);
	Control *_gui_get_drag_preview();
	void _gui_remove_focus_for_window(Node *p_window);
	void _gui_unfocus_control(Control *p_control);