upgrading libraries

back/app/contract/models.py

@@ -1,5 +1,5 @@
 import datetime
-from typing import List, Literal
+from typing import List, Literal, Optional
 from enum import Enum
 
 from pydantic import BaseModel, Field, validator
@@ -52,10 +52,10 @@ class DraftParty(BaseModel):
 class Party(BaseModel):
     entity: Entity
     part: str
-    representative: Entity = None
+    representative: Optional[Entity] = None
     signature_uuid: str
     signature_affixed: bool = False
-    signature_png: str = None
+    signature_png: Optional[str] = None
 
 
 class ProvisionGenuine(BaseModel):
@@ -181,7 +181,7 @@ class Contract(CrudDocument):
     lawyer: Entity = Field(title="Avocat en charge")
     location: str = Field(title="Lieu")
     date: datetime.date = Field(title="Date")
-    label: str = None
+    label: Optional[str] = None
 
     @validator("label", always=True)
     def generate_label(cls, v, values, **kwargs):