Update to actions/github-script v8

[rzuckerm]

[rzuckerm]

It turns out that we are using actions/github-script@v8. However, yumemi-inc/changed-files is using actions/github-script@v7. Unless we can find an alternative or get the maintainer to update this, we'll either need to find a new action or fork this repo.

[rzuckerm]

I logged this issue, yumemi-inc/changed-files#21 . However, I doubt anything will be done since no new development has been done since December 2023.