Upgrade Python 3.8 to Python 3.14

[c1ydehhx]

Since Python 3.8 is EOL, the upgrade is necessery.

Source: https://devguide.python.org/versions/

[c1ydehhx]

@yungyuc
Please assign this to me. But I will solve #180 first.

[yungyuc]

Thank you, @c1ydehhx