Remove serde derive references (#4830)

* remove remaining uses of serde_derive

* fix lockfile

---------

Co-authored-by: João Oliveira <hello@jxs.pt>

consensus/proto_array/src/fork_choice_test_definition.rs

@@ -5,7 +5,7 @@ mod votes;
 
 use crate::proto_array_fork_choice::{Block, ExecutionStatus, ProtoArrayForkChoice};
 use crate::{InvalidationOperation, JustifiedBalances};
-use serde_derive::{Deserialize, Serialize};
+use serde::{Deserialize, Serialize};
 use std::collections::BTreeSet;
 use types::{
     AttestationShufflingId, Checkpoint, Epoch, EthSpec, ExecutionBlockHash, Hash256,

consensus/proto_array/src/proto_array.rs

@@ -1,6 +1,6 @@
 use crate::error::InvalidBestNodeInfo;
 use crate::{error::Error, Block, ExecutionStatus, JustifiedBalances};
-use serde_derive::{Deserialize, Serialize};
+use serde::{Deserialize, Serialize};
 use ssz::four_byte_option_impl;
 use ssz::Encode;
 use ssz_derive::{Decode, Encode};

consensus/proto_array/src/proto_array_fork_choice.rs

@@ -7,7 +7,7 @@ use crate::{
     ssz_container::SszContainer,
     JustifiedBalances,
 };
-use serde_derive::{Deserialize, Serialize};
+use serde::{Deserialize, Serialize};
 use ssz::{Decode, Encode};
 use ssz_derive::{Decode, Encode};
 use std::{