Description of problem:
After upgrading to Fedora 34 I'm not able to run vagrant anymore, any action with vagrant ends with following stacktrace:
```
<internal:/usr/share/rubygems/rubygems/core_ext/kernel_require.rb>:85:in `require': cannot load such file -- rexml/document (LoadError)
        from <internal:/usr/share/rubygems/rubygems/core_ext/kernel_require.rb>:85:in `require'
        from /usr/share/vagrant/gems/gems/vagrant-libvirt-0.1.2/lib/vagrant-libvirt/action/start_domain.rb:2:in `<top (required)>'
        from <internal:/usr/share/rubygems/rubygems/core_ext/kernel_require.rb>:85:in `require'
        from <internal:/usr/share/rubygems/rubygems/core_ext/kernel_require.rb>:85:in `require'
        from /usr/share/vagrant/gems/gems/vagrant-libvirt-0.1.2/lib/vagrant-libvirt/action.rb:50:in `block (2 levels) in action_up'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/action/builtin/call.rb:47:in `call'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/action/warden.rb:48:in `call'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/action/builtin/box_check_outdated.rb:92:in `call'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/action/warden.rb:48:in `call'
        from /usr/share/vagrant/gems/gems/vagrant-sshfs-1.3.5/lib/vagrant-sshfs/action_hostpath_fixup.rb:125:in `call'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/action/warden.rb:48:in `call'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/action/builtin/config_validate.rb:25:in `call'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/action/warden.rb:48:in `call'
        from /usr/share/vagrant/gems/gems/vagrant-sshfs-1.3.5/lib/vagrant-sshfs/action_hostpath_fixup.rb:102:in `call'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/action/warden.rb:48:in `call'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/action/builder.rb:149:in `call'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/action/runner.rb:89:in `block in run'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/util/busy.rb:19:in `busy'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/action/runner.rb:89:in `run'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/machine.rb:240:in `action_raw'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/machine.rb:212:in `block in action'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/environment.rb:613:in `lock'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/machine.rb:198:in `call'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/machine.rb:198:in `action'
        from /usr/share/vagrant/gems/gems/vagrant-2.2.9/lib/vagrant/batch_action.rb:86:in `block (2 levels) in run'
```

Version-Release number of selected component (if applicable):
vagrant-2.2.9-6.fc34.noarch
vagrant-libvirt-0.1.2-3.fc34.noarch

How reproducible:
Just run `vagrant up`.

Steps to Reproduce:
1. cd <directory with vagrantfile>
2. vagrant up

Actual results:
Stack trace above

Expected results:
Machine is started

Additional info: