Apply suggestions from code review: Add ValidatorRegistryDeltaFlag

Co-Authored-By: ChihChengLiang <[email protected]>

Author: hwwhww

eth/beacon/helpers.py

@@ -385,7 +385,7 @@ def get_effective_balance(
 def get_new_validator_registry_delta_chain_tip(current_validator_registry_delta_chain_tip: Hash32,
                                                validator_index: ValidatorIndex,
                                                pubkey: BLSPubkey,
-                                               flag: int) -> Hash32:
+                                               flag: ValidatorRegistryDeltaFlag) -> Hash32:
     """
     Compute the next hash in the validator registry delta hash chain.
     """

eth/beacon/types/validator_registry_delta_block.py

@@ -33,7 +33,7 @@ def __init__(self,
                  latest_registry_delta_root: Hash32,
                  validator_index: ValidatorIndex,
                  pubkey: BLSPubkey,
-                 flag: int) -> None:
+                 flag: ValidatorRegistryDeltaFlag) -> None:
         super().__init__(
             latest_registry_delta_root=latest_registry_delta_root,
             validator_index=validator_index,