fix: address PR #5788 review comments

- Remove dead `env_vars.get("MODEL")` check in _setup_env (always truthy
  since MODEL is set two lines above)
- Fix test_sync_delegation mock: use return_value instead of side_effect
  list and disable planning to prevent StopAsyncIteration on Python 3.10

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/cli/src/crewai_cli/create_agent.py

@@ -776,7 +776,7 @@ def _setup_env(base: Path, llm_model: str) -> None:
         for details in ENV_VARS.get(provider, [])
         if "key_name" in details
     )
-    if already_set and env_vars.get("MODEL"):
+    if already_set:
         return
 
     if provider in ENV_VARS:

lib/crewai/tests/new_agent/test_new_agent.py

@@ -377,12 +377,13 @@ class TestDelegation:
     @patch("crewai.new_agent.executor.aget_llm_response")
     @pytest.mark.asyncio
     async def test_sync_delegation(self, mock_llm_response):
-        mock_llm_response.side_effect = [
-            "Draft article about AI.",  # writer's response
-            "Here is the summary based on the writer's output.",  # manager's response
-        ]
+        mock_llm_response.return_value = "Draft article about AI."
 
-        writer = NewAgent(role="Writer", goal="Write articles")
+        writer = NewAgent(
+            role="Writer",
+            goal="Write articles",
+            settings={"planning_enabled": False},
+        )
         tool = DelegateToCoworkerTool(coworker=writer)
 
         result = tool._run(message="Write an article about AI")