[PRQ#45604] Deletion Request for slacker

MarsSeed [1] filed a deletion request for slacker [2]: Deprecated Slack client from 2017, unlikely to work correctly, or at all. There's a nodejs based successor, as per upstream. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/slacker/