Allow disabling update check at build-time

[pschichtel]

I'm maintaining the stable-versioned AUR package of k0sctl. Users of this expect updates to be driven by just their package management and not the software itself, thus most packaged software disables update checks and notifications, because it is usually "out of the users control" when to upgrade to a new version. Additionally there might be package changes independent of new k0sctl versions (e.g. new build flags, dependency constraints, ...).

It would be nice to have a way to disable the update checking at build-time. I could imagine something using build tags.

[kke]

Yes that's doable. Or remove the update check altogether.