[storages] Use late operations for events

cubicweb_s3storage/storages.py

@@ -28,7 +28,7 @@ import boto3
 from cubicweb import Binary, set_log_methods
 from cubicweb.server.sources.storages import Storage
 from cubicweb.server.edition import EditedEntity
-from cubicweb.server.hook import DataOperationMixIn, Operation
+from cubicweb.server.hook import DataOperationMixIn, LateOperation
 
 
 class S3Storage(Storage):
@@ -167,7 +167,7 @@ class S3Storage(Storage):
         return key + self.suffix
 
 
-class S3AddFileOp(DataOperationMixIn, Operation):
+class S3AddFileOp(DataOperationMixIn, LateOperation):
     containercls = list
 
     def postcommit_event(self):
@@ -192,7 +192,7 @@ class S3AddFileOp(DataOperationMixIn, Operation):
                       eid, attr, storage.bucket, suffixed_key)
 
 
-class S3DeleteFileOp(DataOperationMixIn, Operation):
+class S3DeleteFileOp(DataOperationMixIn, LateOperation):
     containercls = list
 
     def postcommit_event(self):