GPU: Prefer D3D12 over Vulkan when available

src/gpu/SDL_gpu.c

@@ -318,11 +318,11 @@ static const SDL_GPUBootstrap *backends[] = {
 #ifdef SDL_GPU_METAL
     &MetalDriver,
 #endif
-#ifdef SDL_GPU_VULKAN
-    &VulkanDriver,
-#endif
 #ifdef SDL_GPU_D3D12
     &D3D12Driver,
+#endif
+#ifdef SDL_GPU_VULKAN
+    &VulkanDriver,
 #endif
     NULL
 };