fix: support for new graphene-federation

drop support for python 3.8

Author: mak626

graphene_mongo/advanced_types.py

@@ -1,18 +1,17 @@
 import base64
 
 import graphene
+from graphene_federation import shareable
 
 
+@shareable  # Support Graphene Federation v2
 class FileFieldType(graphene.ObjectType):
     content_type = graphene.String()
     md5 = graphene.String()
     chunk_size = graphene.Int()
     length = graphene.Int()
     data = graphene.String()
 
-    # Support Graphene Federation v2
-    _shareable = True
-
     @classmethod
     def _resolve_fs_field(cls, field, name, default_value=None):
         v = getattr(field.instance, field.key)
@@ -38,12 +37,10 @@ def resolve_data(self, info):
         return None
 
 
+@shareable  # Support Graphene Federation v2
 class _CoordinatesTypeField(graphene.ObjectType):
     type = graphene.String()
 
-    # Support Graphene Federation v2
-    _shareable = True
-
     def resolve_type(self, info):
         return self["type"]