Typing is lost when a converter is specified in versions > 6.0.3

Hi,

When i upgrade to the latest version WithConverter returns a plain Javascript Object instead of the requested class.
This seems to be a bug in rxfire. Se this issue as well: https://github.com/FirebaseExtended/rxfire/issues/93

### Version info

**Angular:** ^18.2.0

**Firebase:** ^10.12.0

**AngularFire:** ^18.0.1

### How to reproduce these conditions

**Steps to set up and reproduce**

Create a class, run a query with a converter, debug the output of the query.

### Expected behavior

A query with the withConverter operator should return the class not a plain javascript object.

### Actual behavior

It returns a plain javascript object.

使用 Angular 18.2.0、Firebase 10.12.0 和 AngularFire 18.0.1 通过转换器重现该查询，然后检查为什么 withConverter 返回的是普通 JavaScript 对象，而不是所请求的类。将其行为与相关的 rxfire issue 93 进行比较。当查询结果保留转换后的类时，即视为完成。

由索引模型根据 Issue 内容生成。