zstd: fix install name on macOS (#26518)
zstd: fix install name on macOS (#26518)

Reverting from CMake to Make install caused
`-install_path=/usr/local/lib/libzstd.1.dylib` to be hardcoded into the
zstd. Now we explicitly pass the PREFIX into the build command so that
the correct spack install path is saved.

Fixes #26438 and also the ROOT install issue I had :)
LLNL/spack,LLNL/spack,LLNL/spack,LLNL/spack,LLNL/spack