[rollout] fix external plugins (#4822)

* fix spawn process import plugin

* workflow lint

Author: hjh0119

.github/workflows/close_tale_issue.yaml

@@ -17,4 +17,4 @@ jobs:
           stale-issue-message: 'This issue has been inactive for over 3 months and will be automatically closed in 7 days. If this issue is still relevant, please reply to this message.'
           close-issue-message: 'This issue has been automatically closed due to inactivity. If needed, it can be reopened.'
           stale-issue-label: 'stale'
-          exempt-all-issue-labels: true
+          exempt-all-issue-labels: true

swift/llm/infer/rollout.py

@@ -58,6 +58,7 @@ def safe_set_start_method():
 
 def llm_worker(args: RolloutArguments, data_parallel_rank: int, master_port: int, connection: Connection) -> None:
     # Set required environment variables for DP to work with vLLM
+    args._import_external_plugins()
     os.environ['VLLM_DP_RANK'] = str(data_parallel_rank)
     os.environ['VLLM_DP_RANK_LOCAL'] = str(data_parallel_rank)
     os.environ['VLLM_DP_SIZE'] = str(args.data_parallel_size)
@@ -123,6 +124,8 @@ async def async_llm_worker(args: RolloutArguments, data_parallel_rank: int, mast
 
 
 def llm_worker_entry(*args, **kwargs):
+    rollout_args: RolloutArguments = args[0]
+    rollout_args._import_external_plugins()
     asyncio.run(async_llm_worker(*args, **kwargs))