left over from RS removal

Installation/CMakeLists.txt

@@ -970,19 +970,6 @@ ${CGAL_3RD_PARTY_DEFINITIONS} ${CGAL_Qt6_3RD_PARTY_DEFINITIONS} \
 ${CGAL_DEFINITIONS}" -std=c++17)
     message("COMPILATION OPTIONS ARE :  ${compile_options}")
 
-    if(NOT RS_FOUND AND NOT RS3_FOUND)
-      set(compile_options
-          "${compile_options} \
--DCGAL_ALGEBRAIC_KERNEL_RS_GMPZ_D_1=1 \
--DCGAL_ALGEBRAIC_KERNEL_RS_GMPQ_D_1=1")
-      message(STATUS "Skip RS headers \"CGAL/Algebraic_kernel_rs_gmpq_d_1.h\" \
-and \"CGAL/Algebraic_kernel_rs_gmpz_d_1.h\" because RS_FOUND is false.")
-    else()
-      set(compile_options
-          "${compile_options} \
--DCGAL_USE_MPFI=1 \
--DCGAL_USE_RS=1")
-    endif()
     if(NOT OpenMesh_FOUND)
       set(compile_options
           "${compile_options} \
@@ -1163,16 +1150,12 @@ LEDA_FOUND is false.")
               CMD UNIX_COMMAND "${CMAKE_CXX_COMPILER} ${compile_options_str}
 ${include_options_str} -x c++ ${flag} -H \
 ${CMAKE_CURRENT_SOURCE_DIR}/../${package}/include/${header}"
-              # The header Algebraic_kernel_rs_gmpz_d_1.h is skipped on purpose: it
-              # depends on RS.
             )
             # CMD2 is CMD without the -H option
             separate_arguments(
               CMD2 UNIX_COMMAND "${CMAKE_CXX_COMPILER} ${compile_options_str}
 ${include_options_str} -x c++ ${flag} \
 ${CMAKE_CURRENT_SOURCE_DIR}/../${package}/include/${header}"
-              # The header Algebraic_kernel_rs_gmpz_d_1.h is skipped on purpose: it
-              # depends on RS.
             )
             set(chk_header_name
                 ${CGAL_BINARY_DIR}/package_info/${package}/check_headers/check_${header2}