Please release a new version of the ruby-libvirt gem

A recent has been landed to this repository to resolve changes with where ruby headers are available 43543991

Users on Fedora 34 are bumping into an issue installing ruby-libvirt directly from rubygems using the standard vagrant plugin manager when installing vagrant-libvirt because the system ruby version now provides the headers under a different path.

See https://github.com/vagrant-libvirt/vagrant-libvirt/issues/1269 for the original report of this.