Raise an error if an LLM doesnt return a response (#1548)

src/crewai/llm.py

@@ -1,7 +1,10 @@
+import io
+import logging
+import sys
+import warnings
 from contextlib import contextmanager
 from typing import Any, Dict, List, Optional, Union
-import logging
-import warnings
+
 import litellm
 from litellm import get_supported_openai_params
 
@@ -9,9 +12,6 @@ from crewai.utilities.exceptions.context_window_exceeding_exception import (
     LLMContextLengthExceededException,
 )
 
-import sys
-import io
-
 
 class FilteredStream(io.StringIO):
     def write(self, s):