compilation with Visual Studio might fail because of `WIN32_LEAN_AND_MEAN` redefinition

[firewave]

The downstream Visual Studio compilation fails with the following:

4>D:\a\cppcheck\cppcheck\externals\simplecpp\simplecpp.cpp(11,1): error C2220: the following warning is treated as an error [D:\a\cppcheck\cppcheck\lib\cppcheck.vcxproj]
     4>D:\a\cppcheck\cppcheck\externals\simplecpp\simplecpp.cpp(11,1): warning C4005: 'WIN32_LEAN_AND_MEAN': macro redefinition [D:\a\cppcheck\cppcheck\lib\cppcheck.vcxproj]
       D:\a\cppcheck\cppcheck\lib\check.cpp : message : see previous definition of 'WIN32_LEAN_AND_MEAN' (compiling source file ..\externals\simplecpp\simplecpp.cpp) [D:\a\cppcheck\cppcheck\lib\cppcheck.vcxproj]
``