Keep Windows and nanosvg Setup Ahead of the Added Includes

OrcaSlicer.cpp and several tests set _WIN32_WINNT, WIN32_LEAN_AND_MEAN or NOMINMAX before including Windows.h, and the profile validator defines NANOSVG_IMPLEMENTATION before any libslic3r header. The added includes had landed above those blocks, which broke the Windows build.

tests/slic3rutils/test_filament_bitmap_utils.cpp

@@ -1,11 +1,6 @@
 // recompute_mixed_slot_colors lives in libslic3r_gui; this is the only suite that links it.
 // Same Windows include prologue as test_dev_mapping.cpp (wx pulls in <windows.h>; keep
 // WIN32_LEAN_AND_MEAN / NOMINMAX ahead of the Catch2 headers).
-#include <string>
-#include "libslic3r/Config.hpp"
-#include <vector>
-#include <catch2/catch_test_macros.hpp>
-#include <cstddef>
 #ifdef WIN32
     #ifndef WIN32_LEAN_AND_MEAN
         #define WIN32_LEAN_AND_MEAN
@@ -16,6 +11,12 @@
     #include <Windows.h>
 #endif
 
+#include <string>
+#include "libslic3r/Config.hpp"
+#include <vector>
+#include <catch2/catch_test_macros.hpp>
+#include <cstddef>
+
 #include <catch2/catch_all.hpp>
 
 #include <cmath>