build: target_compile_features now uses CMAKE_CXX_STANDARD

src/cmake/AddMPUnitsModule.cmake

@@ -64,7 +64,13 @@ function(add_mp_units_module name target_name)
 
     # define the target for a module
     add_library(${target_name} ${SCOPE})
-    target_compile_features(${target_name} ${${projectPrefix}TARGET_SCOPE} cxx_std_20)
+
+    if(DEFINED CMAKE_CXX_STANDARD AND CMAKE_CXX_STANDARD GREATER 20)
+        # TODO revise when a fixed version of CMake is released
+        target_compile_features(${target_name} ${${projectPrefix}TARGET_SCOPE} cxx_std_${CMAKE_CXX_STANDARD})
+    else()
+        target_compile_features(${target_name} ${${projectPrefix}TARGET_SCOPE} cxx_std_20)
+    endif()
     target_link_libraries(${target_name} ${${projectPrefix}TARGET_SCOPE} ${ARG_DEPENDENCIES})
     set_target_properties(${target_name} PROPERTIES EXPORT_NAME ${name})