message: Use `fatal!` instead of a panic the `FttExceeded` cases
diff: @@ -1025,12 +1025,12 @@ where
  .collect(),
  ProtocolOutcome::WeAreFaulty => Default::default(),
  ProtocolOutcome::DoppelgangerDetected => Default::default(),
  - // TODO: Replace the panic with the appropriate shutdown effect once that's possible.
  - ProtocolOutcome::FttExceeded => self
  - .effect_builder
  - .set_timeout(Duration::from_millis(FTT_EXCEEDED_SHUTDOWN_DELAY_MILLIS))
  - .then(|_| async move { panic!("shutting down: too many faulty validators") })
  - .ignore(),
  + ProtocolOutcome::FttExceeded => {
  + let eb = self.effect_builder;
  + eb.set_timeout(Duration::from_millis(FTT_EXCEEDED_SHUTDOWN_DELAY_MILLIS))
  + .then(move |_| fatal!(eb, "too many faulty validators"))
  + .ignore()
  + }
  }
  }
  