CMake config/target install dir

Just to note that on CentOS the CMake config and target get installed to different places (I guess because the target is installed using the location from GNUInstallDirs while the config is installed to some dune default location?)

And dune-copasi-config assumes dune-copasi-targets is in the same directory

(I just copy them to the same place for the python Wheels docker, which then works fine, so no urgency to fix at all from my side)

-- Installing: /opt/smelibs/lib/cmake/dune-copasi/dune-copasi-config.cmake
-- Installing: /opt/smelibs/lib/cmake/dune-copasi/dune-copasi-config-version.cmake
-- Installing: /opt/smelibs/share/dune-copasi/config.h.cmake
-- Installing: /opt/smelibs/lib/pkgconfig/dune-copasi.pc
-- Installing: /opt/smelibs/include/dune/copasi/config.h
-- Installing: /opt/smelibs/include/dune/copasi/FC.h
-- Installing: /opt/smelibs/lib64/libdunecopasi.a
-- Installing: /opt/smelibs/lib64/cmake/dune-copasi/dune-copasi-targets.cmake
-- Installing: /opt/smelibs/lib64/cmake/dune-copasi/dune-copasi-targets-release.cmake