Type casting issue when an argument is optional

[bolinocroustibat]

• Python version: 3.11 (could also be reproduced with 3.12 and 3.10)
• minicli version: 0.5.3

Hi, thanks for the useful lib. We recently ran into an unexpected behaviour when hint typing the CLI functions.
Minimal reproduction:

from minicli import cli, run

@cli
async def age(my_age: int = None) -> None:
    if my_age:
        print(type(my_age))

@cli
async def age_optional(my_age: int | None = None) -> None:
    if my_age:
        print(type(my_age))

if __name__ == "__main__":
    run()

When running the commands:

• First command (age) returns int
• Second command (age_optional) incorrectly returns str

Note: same behaviour with Optional[int] and Union[int, None].

Is this expected?