[ci] Use env var to control whether to use S3 bucket in CI (#13634)

tests/entrypoints/llm/test_generate.py

@@ -6,10 +6,9 @@ from typing import List
 import pytest
 
 from vllm import LLM, RequestOutput, SamplingParams
-from vllm.config import LoadFormat
 from vllm.distributed import cleanup_dist_env_and_memory
 
-MODEL_NAME = "s3://vllm-ci-model-weights/distilgpt2"
+MODEL_NAME = "distilbert/distilgpt2"
 
 PROMPTS = [
     "Hello, my name is",
@@ -31,7 +30,6 @@ def llm():
     # pytest caches the fixture so we use weakref.proxy to
     # enable garbage collection
     llm = LLM(model=MODEL_NAME,
-              load_format=LoadFormat.RUNAI_STREAMER,
               max_num_batched_tokens=4096,
               tensor_parallel_size=1,
               gpu_memory_utilization=0.10,