Don't expose header windows.h in catch_all.hpp (#2526)

* Don't expose header windows.h in catch_all.hpp
* Fix generateAmalgamatedFiles.py

src/catch2/catch_all.hpp

@@ -114,7 +114,6 @@
 #include <catch2/internal/catch_unique_ptr.hpp>
 #include <catch2/internal/catch_void_type.hpp>
 #include <catch2/internal/catch_wildcard_pattern.hpp>
-#include <catch2/internal/catch_windows_h_proxy.hpp>
 #include <catch2/internal/catch_xmlwriter.hpp>
 #include <catch2/matchers/catch_matchers_all.hpp>
 #include <catch2/reporters/catch_reporters_all.hpp>

src/catch2/internal/catch_windows_h_proxy.hpp

@@ -21,11 +21,7 @@
 #  define WIN32_LEAN_AND_MEAN
 #endif
 
-#ifdef __AFXDLL
-#include <AfxWin.h>
-#else
 #include <windows.h>
-#endif
 
 #endif // defined(CATCH_PLATFORM_WINDOWS)