Remove self._trimmed_labels

Author: vitorguidi

src/clusterfuzz/_internal/bot/tasks/utasks/__init__.py

@@ -83,7 +83,6 @@ def __init__(self, subtask: _Subtask):
     self.start_time_ns = time.time_ns()
     self._subtask = subtask
     self._labels = None
-    self._trimmed_labels = None
     self.utask_main_failure = None
     self._utask_success_conditions = [
         None,  # This can be a successful return value in, ie, fuzz task