CMakeLists.txt: remove rpath handling

[haampie]

Given the various issues...

1. Bug fix for package [email protected]: set install rpath for cprnc executable spack/spack#47913
2. Bug fix for package cprnc: set install rpath for cprnc executable spack/spack#47505

And since

• CMAKE_MACOSX_RPATH=ON is the default.
• CMAKE_INSTALL_RPATH_USE_LINK_PATH is used, making manually specified install rpaths redundant
• typically users want to set CMAKE_INSTALL_RPATH_USE_LINK_PATH externally, especially when redistributing binaries, to avoid registering rpaths that only exist on a build node

it's better to remove this rpath logic and let users set it from the command line if they really need it (which spack already does).

[haampie]

Hm, looks like CMAKE_INSTALL_RPATH_USE_LINK_PATH=ON is not working because target_link_libraries is used incorrectly.

It should contain paths to libraries instead of linker flags -L<dir> -l<lib>.

I would suggest to use pkg_search_module instead of this custom nc-config, since CMake has the logic to locate the libraries from linker flags from pkg-config, so you can properly use them in target_link_libraries.

[haampie]

@jedwards4b I think this was merged too early given #17 (comment)

CMAKE_INSTALL_RPATH_USE_LINK_PATH does not work when target_link_libraries is used incorrectly like in this package

[jedwards4b]

@haampie Please review #19
Thanks,