Fix lints for Rust 1.63 (#3459)

## Issue Addressed

N/A

## Proposed Changes

Fix clippy lints for latest rust version 1.63. I have allowed the [derive_partial_eq_without_eq](https://rust-lang.github.io/rust-clippy/master/index.html#derive_partial_eq_without_eq) lint as satisfying this lint would result in more code that we might not want and I feel it's not required. 

Happy to fix this lint across lighthouse if required though.

beacon_node/http_api/src/block_id.rs

@@ -90,10 +90,10 @@ impl BlockId {
                         .map_err(warp_utils::reject::beacon_chain_error)?;
                     Ok((*root, execution_optimistic))
                 } else {
-                    return Err(warp_utils::reject::custom_not_found(format!(
+                    Err(warp_utils::reject::custom_not_found(format!(
                         "beacon block with root {}",
                         root
-                    )));
+                    )))
                 }
             }
         }