### 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.
if (_try_parent_dialog(p_from_node)) {
		popup_centered_ratio(p_ratio);
	}
}
void Window::popup_exclusive_centered_clamped(Node *p_from_node, const Size2i &p_size, float p_fallback_ratio) {
	if (_try_parent_dialog(p_from_node)) {
		popup_centered_clamped(p_size, p_fallback_ratio);
	}
}
Rect2i Window::fit_rect_in_parent(Rect2i p_rect, const Rect2i &p_parent_rect) const {
	ERR_READ_THREAD_GUARD_V(Rect2i());
	Size2i limit = p_parent_rect.size;
	if (p_rect.position.x + p_rect.size.x > limit.x) {
		p_rect.position.x = limit.x - p_rect.size.x;
	}
	if (p_rect.position.y + p_rect.size.y > limit.y) {
		p_rect.position.y = limit.y - p_rect.size.y;
	}
	if (p_rect.position.x < 0) {
		p_rect.position.x = 0;
	}
	int title_height = get_flag(Window::FLAG_BORDERLESS) ? 0 : get_theme_constant(SNAME("title_height"));
	if (p_rect.position.y < title_height) {
		p_rect.position.y = title_height;
	}
	return p_rect;
}
Size2 Window::get_contents_minimum_size() const {