[Misc] Add placeholder module (#11501)

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

vllm/config.py

@@ -29,6 +29,7 @@ from vllm.transformers_utils.config import (
     get_hf_text_config, get_pooling_config,
     get_sentence_transformer_tokenizer_config, is_encoder_decoder,
     try_get_generation_config, uses_mrope)
+from vllm.transformers_utils.s3_utils import S3Model
 from vllm.transformers_utils.utils import is_s3
 from vllm.utils import (GiB_bytes, LayerBlockType, cuda_device_count_stateless,
                         get_cpu_memory, print_warning_once, random_uuid,
@@ -372,15 +373,6 @@ class ModelConfig:
 
         """
         if is_s3(model) or is_s3(tokenizer):
-            try:
-                from vllm.transformers_utils.s3_utils import S3Model
-            except ImportError as err:
-                raise ImportError(
-                    "Please install Run:ai optional dependency "
-                    "to use the S3 capabilities. "
-                    "You can install it with: pip install vllm[runai]"
-                ) from err
-
             if is_s3(model):
                 self.s3_model = S3Model()
                 self.s3_model.pull_files(model, allow_pattern=["*config.json"])