[Misc] Remove deprecated files (#17447)

Signed-off-by: chaunceyjiang <chaunceyjiang@gmail.com>

vllm/model_executor/guided_decoding/reasoner/__init__.py

-# SPDX-License-Identifier: Apache-2.0
-
-from __future__ import annotations
-
-from transformers import PreTrainedTokenizer
-
-from vllm.logger import init_logger
-from vllm.model_executor.guided_decoding.reasoner.deepseek_reasoner import (  # noqa: E501
-    DeepSeekReasoner)
-from vllm.model_executor.guided_decoding.reasoner.reasoner import Reasoner
-
-logger = init_logger(__name__)
-
-
-def get_reasoner(tokenizer: PreTrainedTokenizer,
-                 reasoning_backend: str | None) -> Reasoner | None:
-    if reasoning_backend is None:
-        # No reasoning backend specified
-        return None
-    elif reasoning_backend == "deepseek_r1":
-        return DeepSeekReasoner.from_tokenizer(tokenizer)
-    elif reasoning_backend == "granite":
-        logger.warning(
-            "Granite reasoner not yet implemented for structured outputs")
-        return None
-    else:
-        # Raise a warning for unknown reasoning backend and return None
-        # We cannot raise an error here because some reasoning models
-        # may not have a corresponding Reasoner class.
-        logger.warning("Unknown reasoning backend %s for structured outputs ",
-                       reasoning_backend)
-        return None
-
-
-__all__ = ["Reasoner", "get_reasoner"]