1.57.0 lints (#2850)

## Issue Addressed

New rust lints

## Proposed Changes

- Boxing some enum variants
- removing some unused fields (is the validator lockfile unused? seemed so to me)

## Additional Info

- some error fields were marked as dead code but are logged out in areas
- left some dead fields in our ef test code because I assume they are useful for debugging?

Co-authored-by: realbigsean <seananderson33@gmail.com>

beacon_node/beacon_chain/src/beacon_chain.rs

@@ -1602,7 +1602,8 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                 // This method is called for API and gossip attestations, so this covers all unaggregated attestation events
                 if let Some(event_handler) = self.event_handler.as_ref() {
                     if event_handler.has_attestation_subscribers() {
-                        event_handler.register(EventKind::Attestation(v.attestation().clone()));
+                        event_handler
+                            .register(EventKind::Attestation(Box::new(v.attestation().clone())));
                     }
                 }
                 metrics::inc_counter(&metrics::UNAGGREGATED_ATTESTATION_PROCESSING_SUCCESSES);
@@ -1638,7 +1639,8 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
             // This method is called for API and gossip attestations, so this covers all aggregated attestation events
             if let Some(event_handler) = self.event_handler.as_ref() {
                 if event_handler.has_attestation_subscribers() {
-                    event_handler.register(EventKind::Attestation(v.attestation().clone()));
+                    event_handler
+                        .register(EventKind::Attestation(Box::new(v.attestation().clone())));
                 }
             }
             metrics::inc_counter(&metrics::AGGREGATED_ATTESTATION_PROCESSING_SUCCESSES);

beacon_node/beacon_chain/src/state_advance_timer.rs

@@ -41,9 +41,17 @@ const MAX_ADVANCE_DISTANCE: u64 = 4;
 enum Error {
     BeaconChain(BeaconChainError),
     HeadMissingFromSnapshotCache(Hash256),
-    MaxDistanceExceeded { current_slot: Slot, head_slot: Slot },
-    StateAlreadyAdvanced { block_root: Hash256 },
-    BadStateSlot { state_slot: Slot, block_slot: Slot },
+    MaxDistanceExceeded {
+        current_slot: Slot,
+        head_slot: Slot,
+    },
+    StateAlreadyAdvanced {
+        block_root: Hash256,
+    },
+    BadStateSlot {
+        _state_slot: Slot,
+        _block_slot: Slot,
+    },
 }
 
 impl From<BeaconChainError> for Error {
@@ -224,8 +232,8 @@ fn advance_head<T: BeaconChainTypes>(
         // Advancing more than one slot without storing the intermediate state would corrupt the
         // database. Future works might store temporary, intermediate states inside this function.
         return Err(Error::BadStateSlot {
-            block_slot: head_slot,
-            state_slot: state.slot(),
+            _block_slot: head_slot,
+            _state_slot: state.slot(),
         });
     };
 

beacon_node/beacon_chain/src/validator_pubkey_cache.rs

@@ -243,8 +243,8 @@ enum Error {
     /// The file read from disk does not have a contiguous list of validator public keys. The file
     /// has become corrupted.
     InconsistentIndex {
-        expected: Option<usize>,
-        found: usize,
+        _expected: Option<usize>,
+        _found: usize,
     },
 }
 
@@ -296,8 +296,8 @@ impl ValidatorPubkeyCacheFile {
                 indices.insert(pubkey, index);
             } else {
                 return Err(Error::InconsistentIndex {
-                    expected,
-                    found: index,
+                    _expected: expected,
+                    _found: index,
                 });
             }
         }