[Misc] Clean up utils (#27552)

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

tests/utils.py

@@ -45,9 +45,7 @@ from vllm.entrypoints.cli.serve import ServeSubcommand
 from vllm.model_executor.model_loader import get_model_loader
 from vllm.platforms import current_platform
 from vllm.transformers_utils.tokenizer import get_tokenizer
-from vllm.utils import (
-    FlexibleArgumentParser,
-)
+from vllm.utils.argparse_utils import FlexibleArgumentParser
 from vllm.utils.mem_constants import GB_bytes
 from vllm.utils.network_utils import get_open_port
 from vllm.utils.torch_utils import cuda_device_count_stateless