Remove unnecessary serialize of shred data (#5967)

* Remove unnecessary serialize of shred data

* remove obsolete code

* fix golden hash

core/src/chacha.rs

@@ -153,7 +153,7 @@ mod tests {
         hasher.hash(&buf[..size]);
 
         //  golden needs to be updated if blob stuff changes....
-        let golden: Hash = "3LWNjNqC6HncoWUhXbk6cUH8NSM675aZqRPGUC4Zq21H"
+        let golden: Hash = "CLGvEayebjdgnLdttFAweZE9rqVkehXqEStUifG9kiU9"
             .parse()
             .unwrap();