Chore: rm useless import and vars (#22108)

api/tests/integration_tests/workflow/nodes/test_llm.py

@@ -1,5 +1,4 @@
 import json
-import os
 import time
 import uuid
 from collections.abc import Generator
@@ -113,8 +112,6 @@ def test_execute_llm(flask_req_ctx):
         },
     )
 
-    credentials = {"openai_api_key": os.environ.get("OPENAI_API_KEY")}
-
     # Create a proper LLM result with real entities
     mock_usage = LLMUsage(
         prompt_tokens=30,