[consensus] Remove dead code in warnings (#15543)

Author: gregnazario

consensus/src/epoch_manager.rs

@@ -1825,7 +1825,6 @@ pub enum NoRandomnessReason {
     DKGCompletedSessionResourceMissing,
     CompletedSessionTooOld,
     NotInValidatorSet,
-    ConsensusKeyUnavailable,
     ErrConvertingConsensusKeyToDecryptionKey(anyhow::Error),
     TranscriptDeserializationError(bcs::Error),
     SecretShareDecryptionFailed(anyhow::Error),

consensus/src/quorum_store/quorum_store_builder.rs

@@ -129,7 +129,7 @@ pub struct InnerBuilder {
     network_sender: NetworkSender,
     verifier: Arc<ValidatorVerifier>,
     proof_cache: ProofCache,
-    backend: SecureBackend,
+    _backend: SecureBackend,
     coordinator_tx: Sender<CoordinatorCommand>,
     coordinator_rx: Option<Receiver<CoordinatorCommand>>,
     batch_generator_cmd_tx: tokio::sync::mpsc::Sender<BatchGeneratorCommand>,
@@ -205,7 +205,7 @@ impl InnerBuilder {
             network_sender,
             verifier,
             proof_cache,
-            backend,
+            _backend: backend,
             coordinator_tx,
             coordinator_rx: Some(coordinator_rx),
             batch_generator_cmd_tx,