fix(skshader_editor): another instance of windows.h being brought in on linux

Author: Pandapip1

skshader_editor/main.cpp

@@ -2,8 +2,10 @@
 #include "imgui_impl_skg.h"
 #include "imgui_impl_win32.h"
 
+#ifdef _WIN32
 #include <windows.h>
 #include <tchar.h>
+#endif
 #include <stdio.h>
 
 #include "../sk_gpu.h"