Add back missing import

Author: kush-chandra

batch/batch/cloud/utils.py

@@ -2,6 +2,7 @@
 from typing import Any, Dict, Set
 
 from gear.cloud_config import get_azure_config, get_gcp_config
+from hailtop.aiocloud.aioaws import S3AsyncFS
 from hailtop.aiocloud.aioazure import AzureAsyncFS
 from hailtop.aiocloud.aiogoogle import GoogleStorageAsyncFS