Enable media-libs/dumb module library support

Packages describing “dumb” as local USE flag

Package “dumb” Flag Description
media-libs/allegro Enable media-libs/dumb module library support
media-libs/alure Enable media-libs/dumb module library support
games-fps/prboom-plus Enable support for various tracker-style music formats via media-libs/dumb

All packages providing a “dumb” USE flag (3)