Revert "Relocate `llvm-version.h` in codegen to avoid a warning" (#43195)
* Revert "Relocate `llvm-version.h` in codegen to avoid a warning (#43181)"
This reverts commit a0c920c1d977c177d13d9a328fde8f90f506778a.
* remove old define from llvm-version
Co-authored-by: Valentin Churavy <v.churavy@gmail.com>