[mypy] Enable following imports for some directories (#6681)

vllm/entrypoints/openai/serving_engine.py

@@ -5,7 +5,6 @@ from http import HTTPStatus
 from typing import Iterable, Iterator, List, Optional, Tuple, TypedDict, Union
 
 from pydantic import Field
-from transformers import PreTrainedTokenizer, PreTrainedTokenizerFast
 from typing_extensions import Annotated
 
 from vllm.config import ModelConfig
@@ -30,6 +29,7 @@ from vllm.pooling_params import PoolingParams
 from vllm.prompt_adapter.request import PromptAdapterRequest
 from vllm.sampling_params import SamplingParams
 from vllm.sequence import Logprob
+from vllm.transformers_utils.tokenizer_group import AnyTokenizer
 
 logger = init_logger(__name__)
 
@@ -49,8 +49,6 @@ class LoRAModulePath:
 AnyRequest = Union[ChatCompletionRequest, CompletionRequest, DetokenizeRequest,
                    EmbeddingRequest, TokenizeRequest]
 
-AnyTokenizer = Union[PreTrainedTokenizer, PreTrainedTokenizerFast]
-
 
 class TextTokensPrompt(TypedDict):
     prompt: str