fix(streaming): cancel timed-out future before retrying in _put

Prevents accumulation of pending Queue.put coroutines in the event loop
when the producer retries after a timeout. Each timed-out future is now
cancelled before the next attempt.

litellm/litellm_core_utils/streaming_handler.py

@@ -109,6 +109,7 @@ class _SyncIteratorToQueue:
                 fut.result(timeout=0.5)
                 return
             except TimeoutError:
+                fut.cancel()
                 continue
             except Exception:
                 return