Electra minor refactorings (#6839)

N/A


  Fix some typos and other minor refactorings in the electra code. Thanks @jtraglia for bringing them up.

Note to reviewiers: 47803496de is the commit that needs looking into in detail. The rest are very minor refactorings

consensus/state_processing/src/upgrade/electra.rs

@@ -47,10 +47,11 @@ pub fn upgrade_to_electra<E: EthSpec>(
         .enumerate()
         .filter(|(_, validator)| validator.activation_epoch == spec.far_future_epoch)
         .sorted_by_key(|(index, validator)| (validator.activation_eligibility_epoch, *index))
+        .map(|(index, _)| index)
         .collect::<Vec<_>>();
 
     // Process validators to queue entire balance and reset them
-    for (index, _) in pre_activation {
+    for index in pre_activation {
         let balance = post
             .balances_mut()
             .get_mut(index)