I don’t know of any libraries. I can see that on p438 (10.1.10) of Abrimowitz and Stegun there is a recursion formula for Spherical Bessel Functions in using trigonometric functions which seems to be very simple.
My thought is not so much that you use that to evaluate the function directly since there could be a serious performance hit doing that, rather that you use might be able to use it in a script to generate the Fortran code for each order n. Might be an interesting case for using parameter packs in C++