Remove vendored ruby software definition
Remove vendored ruby software definition

Upstream now also uses cache.ruby-lang.org.

felixbuenemann/omnibus-gitlab,aleksandrs-ledovskis/omnibus-gitlab,copystudy/omnibus-gitlab,felixbuenemann/omnibus-gitlab,copystudy/omnibus-gitlab,copystudy/omnibus-gitlab,gitlabhq/omnibus-gitlab,felixbuenemann/omnibus-gitlab,gitlabhq/omnibus-gitlab,gitlabhq/omnibus-gitlab,aleksandrs-ledovskis/omnibus-gitlab,gitlabhq/omnibus-gitlab,aleksandrs-ledovskis/omnibus-gitlab