Fix rust 1.65 lints (#3682)

## Issue Addressed

New lints for rust 1.65

## Proposed Changes

Notable change is the identification or parameters that are only used in recursion

## Additional Info
na

consensus/tree_hash/src/merkle_hasher.rs

@@ -368,7 +368,7 @@ mod test {
     fn context_size() {
         assert_eq!(
             mem::size_of::<HalfNode>(),
-            232,
+            224,
             "Halfnode size should be as expected"
         );
     }