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>

consensus/cached_tree_hash/src/cache_arena.rs

@@ -491,8 +491,8 @@ mod tests {
             subs.push(sub);
         }
 
-        for mut sub in subs.iter_mut() {
-            test_routine(arena, &mut sub);
+        for sub in subs.iter_mut() {
+            test_routine(arena, sub);
         }
     }
 }