Don't mark beta releases as latest release in GitHub Releases

[sneexy-boi]

I think it'd be better to not mark any beta uploads as the "latest" release inside of GitHub releases. This would make it less confusing for any new users and especially if the release is considered to be unstable.

(Realistically; only making this issue as for my use case, I have this weird setup for my linux distribution where I manually get the github releases api for this repository and download the rpm file with AVX2 in the name, which seems like the beta releases do not contain. It's just a tiny little issue I personally have, but nothing important.)