[PRQ#44511] Deletion Request for mate-system-monitor-gtk2

MarsSeed [1] filed a deletion request for mate-system-monitor-gtk2 [2]: Deprecated gtk2-based MATE applet from 2017. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/mate-system-monitor-gtk2/