amtk: remove vala from makedepends
amtk: remove vala from makedepends

Amtk doesn't generate a *.vapi file, Vala projects need to directly use
the GObject Introspection file.

With Meson, generating the vapi file is done with gnome.generate_vapi()
from the GNOME module, and this function isn't used by Amtk.

stahta01/MINGW-packages,lhmouse/MINGW-packages,lhmouse/MINGW-packages,oscarfv/MINGW-packages,JPeterMugaas/MINGW-packages,JPeterMugaas/MINGW-packages,oscarfv/MINGW-packages,JPeterMugaas/MINGW-packages,lhmouse/MINGW-packages,oscarfv/MINGW-packages,oscarfv/MINGW-packages,stahta01/MINGW-packages,JPeterMugaas/MINGW-packages,stahta01/MINGW-packages,JPeterMugaas/MINGW-packages,lhmouse/MINGW-packages,stahta01/MINGW-packages,lhmouse/MINGW-packages,oscarfv/MINGW-packages,lhmouse/MINGW-packages,JPeterMugaas/MINGW-packages,oscarfv/MINGW-packages,stahta01/MINGW-packages,stahta01/MINGW-packages