pyca cryptography removed int_from_bytes, so it need to be removed from preque check

https://github.com/pyca/cryptography/pull/6652/files
function int_from_bytes in cryptography.util will be removed form cryptography 37.0, which will be released in April 26ish, which will break stem's cryptography detection because it try to import them
thoses int from/to bytes isn't really used, so we can safely remove them