[PRQ#50840] Deletion Request for gtksourceview

MarsSeed [1] filed a deletion request for gtksourceview [2]: Unneeded GNOME2 component from 2007. Safe to delete after dropping its defunct consumer, screem, from 2005 (PRQ#48288). [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/gtksourceview/