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/http_api/tests/tests.rs

@@ -2310,7 +2310,7 @@ impl ApiTester {
             self.attestations
                 .clone()
                 .into_iter()
-                .map(|attestation| EventKind::Attestation(attestation))
+                .map(|attestation| EventKind::Attestation(Box::new(attestation)))
                 .collect::<Vec<_>>()
                 .as_slice()
         );