fix jax top_k

Author: JuliaPoo

array_api_compat/jax/__init__.py

@@ -43,7 +43,7 @@ def top_k(
         slice = slice_start + (s_[:k],)
         topk_indices = indices_array[slice]
 
-    topk_indices = topk_indices.astype(np.int_)
+    topk_indices = topk_indices.astype(int_)
     topk_values = take_along_axis(arr, topk_indices, axis=axis)
     return (topk_values, topk_indices)