make ruff happy again

gso/utils/helpers.py

@@ -230,7 +230,8 @@ class BaseSiteValidatorModel(BaseModel):
     def field_must_be_unique(cls, value: str | int, info: ValidationInfo) -> str | int:
         """Validate that a field is unique."""
         if not info.field_name:
-            raise ValueError("Field name is required")
+            msg = "Field name must be provided."
+            raise ValueError(msg)
 
         validate_site_fields_is_unique(info.field_name, value)