feat: use ld.so.conf.d to add paths
As discussed in https://github.com/eic/EICrecon/issues/1030#issuecomment-1740159194, this should be equivalent as setting LD_LIBRARY_PATH, but doesn't override RPATH entries inside ELF files. @veprbl
As discussed in https://github.com/eic/EICrecon/issues/1030#issuecomment-1740159194, this should be equivalent as setting LD_LIBRARY_PATH, but doesn't override RPATH entries inside ELF files. @veprbl