Clippy 1.49.0 updates and dht persistence test fix (#2156)

## Issue Addressed

`test_dht_persistence` failing

## Proposed Changes

Bind `NetworkService::start` to an underscore prefixed variable rather than `_`.  `_` was causing it to be dropped immediately

This was failing 5/100 times before this update, but I haven't been able to get it to fail after updating it

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

consensus/proto_array/src/ssz_container.rs

@@ -4,7 +4,6 @@ use crate::{
 };
 use ssz_derive::{Decode, Encode};
 use std::collections::HashMap;
-use std::iter::FromIterator;
 use types::{Epoch, Hash256};
 
 #[derive(Encode, Decode)]
@@ -41,7 +40,7 @@ impl From<SszContainer> for ProtoArrayForkChoice {
             justified_epoch: from.justified_epoch,
             finalized_epoch: from.finalized_epoch,
             nodes: from.nodes,
-            indices: HashMap::from_iter(from.indices.into_iter()),
+            indices: from.indices.into_iter().collect::<HashMap<_, _>>(),
         };
 
         Self {