fix compilation windows

Author: minhthuc2502

src/ops/flash_attention_gpu.cu

@@ -1,7 +1,6 @@
 #include "ctranslate2/ops/flash_attention.h"
 #include "ctranslate2/ops/flash-attention/flash.h"
 #include "ctranslate2/ops/flash-attention/static_switch.h"
-#include "ctranslate2/ops/flash-attention/utils.h"
 #include "ctranslate2/ops/transpose.h"
 #include "ctranslate2/ops/slide.h"
 #include "cuda/utils.h"