feat: updated random Big Int to be roughly the same length as posiedon hash

tests/utils.ts

@@ -1,7 +1,9 @@
 import { faker } from '@faker-js/faker';
 
 export function randBigint(): bigint {
-  return faker.number.bigInt();
+  const min = 1000000000000000000000000000000000000000000000000000000000000000000000000000n;
+  const max = 9999999999999999999999999999999999999999999999999999999999999999999999999999n;
+  return faker.number.bigInt({ min: min, max: max });
 }
 
 export function randomRoomName(min = 5, max = 20): string {