[numpy] Fix users of NumPy APIs that are removed in NumPy 2.0.

This change migrates users of APIs removed in NumPy 2.0 to their recommended replacements (https://numpy.org/devdocs/numpy_2_0_migration_guide.html).

PiperOrigin-RevId: 655904507

ffn/inference/segmentation.py

@@ -205,7 +205,7 @@ def remap_input(x):
       orig_values_map, x = np.unique(x, return_inverse=True)
       if len(orig_values_map) > max_uint32:
         raise ValueError('More than 2**32-1 unique labels not supported')
-      x = np.cast[np.uint64](x)
+      x = np.asarray(x, dtype=np.uint64)
       if orig_values_map[0] != 0:
         orig_values_map = np.concatenate(
             [np.array([0], dtype=np.uint64), orig_values_map])