Fix Rust 1.61 clippy lints (#3192)

## Issue Addressed

This fixes the low-hanging Clippy lints introduced in Rust 1.61 (due any hour now). It _ignores_ one lint, because fixing it requires a structural refactor of the validator client that needs to be done delicately. I've started on that refactor and will create another PR that can be reviewed in more depth in the coming days. I think we should merge this PR in the meantime to unblock CI.

beacon_node/beacon_chain/src/block_verification.rs

@@ -53,6 +53,7 @@ use crate::{
     },
     metrics, BeaconChain, BeaconChainError, BeaconChainTypes,
 };
+use derivative::Derivative;
 use eth2::types::EventKind;
 use execution_layer::PayloadStatus;
 use fork_choice::{ForkChoice, ForkChoiceStore, PayloadVerificationStatus};
@@ -537,7 +538,8 @@ pub fn signature_verify_chain_segment<T: BeaconChainTypes>(
 
 /// A wrapper around a `SignedBeaconBlock` that indicates it has been approved for re-gossiping on
 /// the p2p network.
-#[derive(Debug)]
+#[derive(Derivative)]
+#[derivative(Debug(bound = "T: BeaconChainTypes"))]
 pub struct GossipVerifiedBlock<T: BeaconChainTypes> {
     pub block: SignedBeaconBlock<T::EthSpec>,
     pub block_root: Hash256,