[Chore] Move tokenizer initialization methods (#29793)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

benchmarks/benchmark_serving_structured_output.py

@@ -46,7 +46,7 @@ from tqdm.asyncio import tqdm
 from transformers import PreTrainedTokenizerBase
 
 try:
-    from vllm.transformers_utils.tokenizer import get_tokenizer
+    from vllm.tokenizers import get_tokenizer
 except ImportError:
     from backend_request_func import get_tokenizer