Remove old way of account hashing

Account data hashing used to use different ways of hashing on different
clusters.  That is no longer the case, but the old code still existed.
This commit removes that old, now used code.

**NOTE** The golden hash values in bank.rs needed to be updated.  Since
the original code that selected the hash algorithm used `if >` instead
of `if >=`, this meant that the genesis block's hash _always_ used the
old hashing method, which is no longer valid.

Validated by running `cargo test` successfully.

runtime/tests/accounts.rs

@@ -113,7 +113,7 @@ fn test_bad_bank_hash() {
         for (key, account) in &account_refs {
             assert_eq!(
                 db.load_account_hash(&ancestors, &key),
-                AccountsDb::hash_account(some_slot, &account, &key, &ClusterType::Development)
+                AccountsDb::hash_account(some_slot, &account, &key)
             );
         }
         existing.clear();