Fix dependency resolution where default gems are included
Fix dependency resolution where default gems are included

    Parts of the stdlib which have been externalized but are still
    included within Ruby introduce issues when pinning Vagrant's
    dependencies to resolve plugin installs. When determining
    Vagrant's dependency list prior to solution generation, check
    the specification and ignore any default gems to prevent
    pinning versions that are not actual dependencies.

sni/vagrant,sni/vagrant,sni/vagrant,sni/vagrant