Update to Vagrant 2.2.16.
    
    Resolves: rhbz#1872307
    
     - Enhance .spec file.
     - Fix compatibility with Ruby 3.0.
     - Add rexml dependency, as it's no longer a default gem with Ruby 3.0.
     - Apply net-ssh patches apply regardless of net-ssh version.
     - Add bcond_with for ed25519, and also respective (Build)Requires,
       as the dependency is monkey-patched for vagrant use.