Bump PHP Version

Feature Request

Currently this package requires PHP > 8.0.2, however both 8.0 and 8.1 are EOL.

I propose bumping with a major release to PHP8.5.

For several tickets it would be nice if we could do this:

• Move to PHPUnit 13 (https://github.com/thephpleague/flysystem/issues/1867)
• PhpseclibV4 (https://github.com/thephpleague/flysystem/issues/1921)
• #1691

Summary

I believe its easier to contribute to projects if they use modern PHP versions. Specifically the improved typing makes it easier for better tools like PHPStan to work on the code base, which in turn makes it easier for developers to be confident when making changes.

Edit: ofcourse I'm happy to make the PR, I don't expect open source maintainers to feel obliged to do the work I request on demand!