[Core] RayWorkerVllm --> WorkerWrapper to reduce duplication (#4024)

[Core] replace narrow-usage RayWorkerVllm to general WorkerWrapper to reduce code duplication (#4024)

tests/distributed/test_pynccl.py

@@ -1,18 +1,18 @@
 import multiprocessing
-import os
 
 import pytest
 import torch
 
 from vllm.distributed.device_communicators.pynccl import (NCCLCommunicator,
                                                           ncclGetUniqueId)
+from vllm.utils import update_environment_variables
 
 
 def distributed_run(fn, world_size):
     number_of_processes = world_size
     processes = []
     for i in range(number_of_processes):
-        env = os.environ.copy()
+        env = {}
         env['RANK'] = str(i)
         env['LOCAL_RANK'] = str(i)
         env['WORLD_SIZE'] = str(number_of_processes)
@@ -32,8 +32,7 @@ def update_env(fn):
     # so we need to pass the environment variables as arguments
     # and update the environment variables in the function
     def wrapper(env):
-        import os
-        os.environ.update(env)
+        update_environment_variables(env)
         fn()
 
     return wrapper