fix(research): replace deprecated np.int with int in mobilenet_v3 (#13609)

The use of `np.int` was deprecated in NumPy 1.20 and completely 
removed in NumPy 1.24. This change caused `_reduce_consecutive_layers` 
to fail with an AttributeError when using NumPy 1.24+.

This commit replaces `np.int` with the built-in `int` function 
to ensure compatibility with modern NumPy versions. 

Affected file: research/slim/nets/mobilenet/mobilenet_v3.py

Author: llukito

research/slim/nets/mobilenet/mobilenet_v3.py

@@ -748,7 +748,7 @@ def _reduce_consecutive_layers(conv_defs, start_id, end_id, multiplier=0.5):
   defs = copy.deepcopy(conv_defs)
   for d in defs['spec'][start_id:end_id+1]:
     d.params.update({
-        'num_outputs': np.int(np.round(d.params['num_outputs'] * multiplier))
+        'num_outputs': int(np.round(d.params['num_outputs'] * multiplier))
     })
   return defs