[PRQ#45500] Deletion Request for mumps4

MarsSeed [1] filed a deletion request for mumps4 [2]: This orphan legacy version was only used by the now-broken and similarly abandoned salome packages from same year. Safe to delete this now. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/mumps4/