fix(core): Restore export of ZoneService

packages/core/src/service/index.ts

@@ -34,5 +34,5 @@ export * from './services/shipping-method.service';
 export * from './services/tax-category.service';
 export * from './services/tax-rate.service';
 export * from './services/user.service';
-export * from './services/user.service';
+export * from './services/zone.service';
 export * from './transaction/transactional-connection';