Refactor: Remove empty bot constructors that only call super()

**Suggestion:** Remove the empty constructor since it only calls the superclass constructor and adds unnecessary boilerplate. [general, importance: 5]

```diff
-  constructor() {
-    super();
-  }
+  // constructor omitted since default inherited constructor is sufficient
```

_Originally posted by @PeterBot in https://github.com/ai-shifu/ChatALL/pull/1005#discussion_r2051138623_
            