Implement library cleanup #5
Description
Most of the CRT libraries have init and cleanup routines. I don't think it is strictly necessary to invoke the cleanup routines (the kernel will clean up after us), but it would be best practice to do so. This can be tricky to implement as the cleanup routines must be called after all AWS resources are freed (so after all finalizers). We can try to implement something based on https://github.com/JuliaLang/julia/pull/20124/files