fix: Workflow execution decimal cannot be serialized (#2372)

apps/application/models/application.py

@@ -7,6 +7,7 @@
     @desc:
 """
 import datetime
+import decimal
 import json
 import uuid
 
@@ -140,6 +141,8 @@ class DateEncoder(json.JSONEncoder):
             return str(obj)
         if isinstance(obj, datetime.datetime):
             return obj.strftime("%Y-%m-%d %H:%M:%S")
+        if isinstance(obj, decimal.Decimal):
+            return float(obj)
         else:
             return json.JSONEncoder.default(self, obj)