*: add validator to ensure JSON Fields only receive dicts

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

authentik/core/api/groups.py

@@ -1,13 +1,17 @@
 """Groups API Viewset"""
+from rest_framework.fields import JSONField
 from rest_framework.serializers import ModelSerializer
 from rest_framework.viewsets import ModelViewSet
 
+from authentik.core.api.utils import is_dict
 from authentik.core.models import Group
 
 
 class GroupSerializer(ModelSerializer):
     """Group Serializer"""
 
+    attributes = JSONField(validators=[is_dict])
+
     class Meta:
 
         model = Group