cmake HAS_CXX23 examples

erthink/libmdbx CMakeLists.txt :526 

list(FIND CMAKE_CXX_COMPILE_FEATURES cxx_std_23 HAS_CXX23)

erthink/libmdbx CMakeLists.txt :533 

elseif(NOT HAS_CXX23 LESS 0 AND NOT (CMAKE_COMPILER_IS_CLANG AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 12))