fix: Remove LOGGER.exception() line (#1087)

Author: mukund-ananthu

google/cloud/pubsub_v1/publisher/_batch/thread.py

@@ -290,7 +290,6 @@ def _commit(self) -> None:
                 # Failed to publish batch.
                 self._batch_done_callback(batch_transport_succeeded)
 
-            _LOGGER.exception("Failed to publish %s messages.", len(self._futures))
             return
 
         end = time.time()