Use an immutable view in GeyserDefineCommandsEvent

Methods to properly register/unregister commands are provided in the command manager

api/geyser/src/main/java/org/geysermc/geyser/api/event/lifecycle/GeyserDefineCommandsEvent.java

@@ -36,8 +36,7 @@ import java.util.Map;
  * Called when commands are defined within Geyser.
  *
  * @param commandManager the command manager
- * @param commands a mutable list of the currently
- *                 registered default commands
+ * @param commands an immutable view of the default commands
  */
 public record GeyserDefineCommandsEvent(@NonNull CommandManager commandManager, @NonNull Map<String, Command> commands) implements Event {
 }

core/src/main/java/org/geysermc/geyser/command/GeyserCommandManager.java

@@ -70,7 +70,7 @@ public abstract class GeyserCommandManager extends CommandManager {
             register(new StopCommand(geyser, "stop", "geyser.commands.stop.desc", "geyser.command.stop"));
         }
 
-        this.geyser.eventBus().fire(new GeyserDefineCommandsEvent(this, this.commands));
+        this.geyser.eventBus().fire(new GeyserDefineCommandsEvent(this, this.commands()));
     }
 
     @Override