[PRQ#42428] Deletion Request for futhark-nightly

MarsSeed [1] filed a deletion request for futhark-nightly [2]: Unmaintained development version package from 2020. Not needed; stable variant is much newer than this. Safe to delete, nothing depends on it. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/futhark-nightly/