fix lint

Author: spypsy

yarn-project/validator-client/src/validator.ts

@@ -1,7 +1,7 @@
 import type { BlobClientInterface } from '@aztec/blob-client/client';
 import { type Blob, getBlobsPerL1Block } from '@aztec/blob-lib';
 import type { EpochCache } from '@aztec/epoch-cache';
-import { BlockNumber, EpochNumber, SlotNumber } from '@aztec/foundation/branded-types';
+import { BlockNumber, CheckpointNumber, EpochNumber, SlotNumber } from '@aztec/foundation/branded-types';
 import { Fr } from '@aztec/foundation/curves/bn254';
 import { TimeoutError } from '@aztec/foundation/error';
 import type { EthAddress } from '@aztec/foundation/eth-address';