main: Remove declaration of old deprecated functions
main: Remove declaration of old deprecated functions

These were removed already

flatpak/flatpak,alexlarsson/xdg-app,handsome-feng/flatpak,flatpak/flatpak,matthiasclasen/flatpak,flatpak/flatpak,GeorgesStavracas/flatpak,handsome-feng/flatpak,alexlarsson/xdg-app,handsome-feng/flatpak,amigadave/flatpak,GeorgesStavracas/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,GeorgesStavracas/flatpak,amigadave/flatpak,handsome-feng/flatpak,GeorgesStavracas/flatpak,matthiasclasen/flatpak,handsome-feng/flatpak,alexlarsson/xdg-app,alexlarsson/xdg-app,amigadave/flatpak,amigadave/flatpak,flatpak/flatpak,GeorgesStavracas/flatpak,flatpak/flatpak,matthiasclasen/flatpak