[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: 655939518

seqio/evaluation_test.py

@@ -1323,7 +1323,7 @@ def test_metric_with_arbitrary_model_input_types(self):
             {"targets": np.ones(2**6).reshape((2, 2, 2, 2, 2, 2))},
         ],
         [
-            {"targets": np.zeros((2, 2), dtype=np.complex_)},
+            {"targets": np.zeros((2, 2), dtype=np.complex128)},
         ],
         [
             {"targets": ["hello darkness, my old friend..."]},