### Godot version

4.0.rc

### System information

Any

### Issue description

If the RESET animation is generated at the same time as the Bezier track is generated, the bezier edit button will not be active.

![image](https://user-images.githubusercontent.com/61938263/218256176-88b1b196-7b6b-4404-84ad-e8694f23bb1b.png)

Also, if you delete a track in the Bezier Editor, or in undo redo, it will not update correctly.

### Steps to reproduce

![image](https://user-images.githubusercontent.com/61938263/218256230-4b0219d5-87e4-453a-8294-59f8feb0cfd5.png)


### Minimal reproduction project

N/A
if (!animation.is_valid()) {
		return 0;
	}
	return type_icon->get_height();
}
Rect2 AnimationTrackEdit::get_key_rect(int p_index, float p_pixels_sec) {
	if (!animation.is_valid()) {
		return Rect2();
	}
	Rect2 rect = Rect2(-type_icon->get_width() / 2, 0, type_icon->get_width(), get_size().height);
	
	rect.position.x -= rect.size.x * 0.5;
	rect.size.x *= 2;
	return rect;
}
bool AnimationTrackEdit::is_key_selectable_by_distance() const {