Replace tensorflow.compat.v2 import with tensorflow in vocabularies.

PiperOrigin-RevId: 610530663

seqio/vocabularies.py

@@ -22,7 +22,7 @@
 from typing import Any, ClassVar, Dict, Iterable, Optional, Sequence, Union
 
 from absl import logging
-import tensorflow.compat.v2 as tf
+import tensorflow as tf
 import tensorflow_text as tf_text
 
 from sentencepiece import sentencepiece_model_pb2