[PRQ#48258] Deletion Request for clang8

MarsSeed [1] filed a deletion request for clang8 [2]: Legacy clang version from 2019. Conflicts with repo's clang. It is not a drop-in replacement. Therefor this package is not allowed to be kept on AUR as per submission guidelines. Safe to delete: nothing requires this build. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/clang8/