Update llvm-sys

Update llvm-sys dependency to support llvm 15+
With llvm 15 and newer build fails bc of undefined symbols LLVMBuildCall and LLVMBuildLoad in llvm-sys crate. Please change link for this crate or fork it, changes to support newer llvm is pretty trivial.

We tested llvm 15+ (a few) and the performance was worse than the current version (13). You may fork it and change it to LLVM 15 in the install_deb.sh file if the performance is not a major factor for you.