[PEP 686] When running on python 3.15, remove encoding="UTF-8

[kasium]

Hi,

it would be great if this tool could remove UTF-8 encoding from e.g. open calls as with PEP 686 UTF-8 is the default.

[asottile]

makes sense. but we don't implement anything until rc1 because I've been burned in the past by late changes in releases

[kasium]

Sure, thanks for considering it!