Fix initial WIN32 detection

DDSTextureLoader/DDSTextureLoader12.h

@@ -16,7 +16,7 @@
 
 #pragma once
 
-#if defined(WIN32) || defined(WINAPI_FAMILY)
+#if defined(WIN32) || defined(_WIN32)
 #include <d3d12.h>
 #else
 #include <wsl/winadapter.h>

DirectXTex/DirectXTex.h

@@ -17,7 +17,7 @@
 #include <utility>
 #include <vector>
 
-#if defined(WIN32) || defined(WINAPI_FAMILY)
+#if defined(WIN32) || defined(_WIN32)
 #if !defined(__d3d11_h__) && !defined(__d3d11_x_h__) && !defined(__d3d12_h__) && !defined(__d3d12_x_h__) && !defined(__XBOX_D3D12_X__)
 #ifdef _GAMING_XBOX_SCARLETT
 #include <d3d12_xs.h>

DirectXTex/DirectXTexP.h

@@ -70,7 +70,7 @@
 #pragma clang diagnostic ignored "-Wunknown-pragmas"
 #endif
 
-#if defined(WIN32) || defined(WINAPI_FAMILY)
+#if defined(WIN32) || defined(_WIN32)
 #ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
 #endif