style: format Python files with Ruff

main.py

@@ -30,6 +30,7 @@ class todocreate(BaseModel):
 
         return value
 
+
 class todoupdate(BaseModel):
     completion: bool | None = None
     task: str | None = Field(
@@ -48,16 +49,15 @@ class todoupdate(BaseModel):
             raise ValueError("task must not be blank")
 
         return value
-    
+
     @model_validator(mode="after")
     def at_least_one_field_must_be_provided(self) -> Self:
         if self.task is None and self.completion is None:
-            raise ValueError(
-                "task or completion must be provided"
-            )
+            raise ValueError("task or completion must be provided")
 
         return self
 
+
 class todoresponse(BaseModel):
     id: int
     task: str