Rust 1.54.0 lints (#2483)

## Issue Addressed

N/A

## Proposed Changes

- Removing a bunch of unnecessary references
- Updated `Error::VariantError` to `Error::Variant`
- There were additional enum variant lints that I ignored, because I thought our variant names were fine
- removed `MonitoredValidator`'s `pubkey` field, because I couldn't find it used anywhere. It looks like we just use the string version of the pubkey (the `id` field) if there is no index

## Additional Info



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

consensus/proto_array/src/proto_array_fork_choice.rs

@@ -148,8 +148,8 @@ impl ProtoArrayForkChoice {
         let deltas = compute_deltas(
             &self.proto_array.indices,
             &mut self.votes,
-            &old_balances,
-            &new_balances,
+            old_balances,
+            new_balances,
         )
         .map_err(|e| format!("find_head compute_deltas failed: {:?}", e))?;