blessed-builds: Allow uploads to 'amber'
currently we only allow uploads to amber-phone
however several packages make sense in pureos proper as well:
- chatty (not yet uploaded)
- libhandy (by hand)
- phosh (by hand)
- phoc (by hand)
These are currently either uploaded there by hand or not at all, let's fix that by allowing amber
as upload target as well and build against amber-proposed-updates
in this case.
/cc @jeremiah.foster @arno.bauernoppel if that sounds sensible