Force opts to be options

cb6f3e5 introduced a change to the method airty of machine actions to remove the
`extra_env` attribute.

- Fixes #4960

plugins/commands/package/command.rb

@@ -80,7 +80,7 @@ module VagrantPlugins
           acc
         end
 
-        vm.action(:package, opts)
+        vm.action(:package, **opts)
       end
     end
   end