Electra attestation changes from Lions review (#5971)

* dedup/cleanup and remove unneeded hashset use

* remove irrelevant TODOs

consensus/state_processing/src/common/get_attesting_indices.rs

@@ -47,7 +47,6 @@ pub mod attesting_indices_electra {
     use std::collections::HashSet;
 
     use crate::per_block_processing::errors::{AttestationInvalid as Invalid, BlockOperationError};
-    use itertools::Itertools;
     use safe_arith::SafeArith;
     use types::*;
 
@@ -96,7 +95,7 @@ pub mod attesting_indices_electra {
         aggregation_bits: &BitList<E::MaxValidatorsPerSlot>,
         committee_bits: &BitVector<E::MaxCommitteesPerSlot>,
     ) -> Result<Vec<u64>, BeaconStateError> {
-        let mut output: HashSet<u64> = HashSet::new();
+        let mut attesting_indices = vec![];
 
         let committee_indices = get_committee_indices::<E>(committee_bits);
 
@@ -128,8 +127,7 @@ pub mod attesting_indices_electra {
                 })
                 .collect::<HashSet<u64>>();
 
-            output.extend(committee_attesters);
-
+            attesting_indices.extend(committee_attesters);
             committee_offset.safe_add_assign(beacon_committee.committee.len())?;
         }
 
@@ -138,10 +136,9 @@ pub mod attesting_indices_electra {
             return Err(BeaconStateError::InvalidBitfield);
         }
 
-        let mut indices = output.into_iter().collect_vec();
-        indices.sort_unstable();
+        attesting_indices.sort_unstable();
 
-        Ok(indices)
+        Ok(attesting_indices)
     }
 
     pub fn get_committee_indices<E: EthSpec>(

consensus/state_processing/src/per_block_processing/signature_sets.rs

@@ -326,7 +326,6 @@ where
         genesis_validators_root,
     );
 
-    // TODO(electra), signing root isnt unique in the case of electra
     let message = indexed_attestation.data().signing_root(domain);
 
     Ok(SignatureSet::multiple_pubkeys(signature, pubkeys, message))