Don't use Walrus Operator when return value of function is zero

[lyoutakoduka]

Use following statement instead of walrus operator.

value: int | None = function()
if value is None:
    ...

https://github.com/lyoutakoduka/spartaproject/blob/4a918756f77e3f53232057f404ea0ddcc0bd73ac/pyspartaproj/script/string/base_name_elements.py#L63