Do you mean that there are absolutely no other classes that you can take, or no other APs?
If you have already taken a course load that your GC considers to be in the ‘most rigorous’ category (which does not mean every advanced class offered), then taking extra APs just to take them will not be particularly meaningful to college admissions. What would hurt you is taking an AP in a subject for which you are not prepared and not doing well in it.
Do any of the colleges you are considering say that they prefer 4 years of a FL? Some do.