I use vagrant installed as an rpm from upstream (hashicorp repo), along with vagrant-libvirt installed as a plugin, not as an rpm. When I updated my workstation from F35 to F36 beta, I noted that the upgrade installed vagrant and vagrant-libvirt as rpms from the Fedora repo.
After a successful and uneventful upgrade to Fedora 36 beta (excellent work!) I tested vagrant in an existing vagrant project using the rpms as installed. Vagrant up failed. I also tested vagrant plugin update, which also failed. I was not surprised.
The fix was simple. Uninstall the fedora vagrant rpm which will also uninstall dependencies including the vagrant-libvirt rpm. And install the upstream vagrant rpm. See this post (https://github.com/vagrant-libvirt/vagrant-libvirt/discussions/1478#discussion-4007763) for the steps followed if interested.
If you are new to vagrant, then the fedora rpms should work fine. Those who have been using vagrant upstream may encounter the problem I did.
regards