Not compatible with 2024-02-06 "Kaos"

On Kaos I get this error:

```
dokuwiki\Exception\FatalException: Declaration of action_plugin_discussion::register(&$contr) must be compatible with dokuwiki\Extension\ActionPlugin::register(dokuwiki\Extension\EventHandler $controller)
An unforeseen error has occured. This is most likely a bug somewhere. It might be a problem in the discussion plugin.
```