fix info schema

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@orionprotocol/sdk",
-  "version": "0.19.89-rc19",
+  "version": "0.19.89-rc20",
   "description": "Orion Protocol SDK",
   "main": "./lib/index.cjs",
   "module": "./lib/index.js",

src/services/Integrator/schemas/info-schema.ts

@@ -1,9 +1,11 @@
 import { z } from 'zod';
-import { hexStringSchema } from './util-schemas.js';
+import { ethers } from 'ethers';
 
 const infoSchema = z.object({
   blockNumber: z.number().int().nonnegative(),
-  blockHash: hexStringSchema,
+  blockHash: z.string().refine((v) => v.length === 0 || ethers.utils.isHexString(v), {
+    message: 'blockHash must be a valid hex string or empty',
+  }),
   timeRequest: z.number().int().nonnegative(),
   timeAnswer: z.number().int().nonnegative(),
   changes: z.number().int().nonnegative(),