GRUB 2.x has moved to [core]. With this move support for GRUB legacy
(i.e. version 0.9x) is dropped, which is now moved to AUR.
Although GRUB legacy will not be removed from your system and will stay fully functional, you should consider upgrading to GRUB version 2.x, or one of the other supported bootloaders.
Please consult the GRUB wiki page for detailed installation instructions for GRUB version 2.x.