[Chore]: Reorganize gguf utils funtions under transformers_utils (#29891)

Signed-off-by: Isotr0py <mozf@mail2.sysu.edu.cn>

vllm/engine/arg_utils.py

@@ -86,8 +86,9 @@ from vllm.transformers_utils.config import (
     is_interleaved,
     maybe_override_with_speculators,
 )
+from vllm.transformers_utils.gguf_utils import is_gguf
 from vllm.transformers_utils.repo_utils import get_model_path
-from vllm.transformers_utils.utils import is_cloud_storage, is_gguf
+from vllm.transformers_utils.utils import is_cloud_storage
 from vllm.utils.argparse_utils import FlexibleArgumentParser
 from vllm.utils.mem_constants import GiB_bytes
 from vllm.utils.network_utils import get_ip