Use atotto/clipboard fork

[samos667]

Is your feature request related to a problem? Please describe.
https://github.com/atotto/clipboard was unmaintained during 4 years and have not merged these useful request like atotto/clipboard#64

There is a fork initied by the devs of https://github.com/gopasspw/gopass I think it would be nice to move to this as clipboard stuff is really sensible. At the first look I don't see breaking change implemented.

[MartinodF]

Please consider switching if at all possible. We now have a replace entry in our go.mod because the very aggressive multiple PATH lookups in init() were creating all sorts of issues.