`set(CMAKE_CXX_STANDARD 23)` doesn't work for gcc 11
I think the following lines might be missed in Modules/Compiler/GNU-CXX.cmake
if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 11.0)
set(CMAKE_CXX23_STANDARD_COMPILE_OPTION "-std=c++23")
set(CMAKE_CXX23_EXTENSION_COMPILE_OPTION "-std=gnu++23")
endif()