overriding model property with more specific object type doesn't work

Describe the bug
When an object schema derives from another object schema using allOf, and redeclares a property that had an object type to use a different object type, the generated code uses the old type for that property.

OpenAPI Spec File
https://gist.github.com/eli-bl/d5658d6714e1c9ef544ef1fc8902960a

With this example, the type of SpecialTask.result in the generated code should be SpecialTaskOutputData. Instead it is being declared as BaseTaskResult, the same as BaseTask.result.

Desktop (please complete the following information):

• OS: macOS 14.5
• Python Version: 3.8.15
• openapi-python-client version: 0.21.5

首先使用报告中链接的 OpenAPI 规范重现该问题，并检查为 BaseTask 和 SpecialTask 生成的模型。跟踪继承的和重新声明的对象属性如何被解析；当 SpecialTask.result 使用 SpecialTaskOutputData 类型而不是 BaseTaskResult 生成时，即表示完成。