docs: update py_wheel to show prefix stripping

While talking to a user, they didn't realize py_wheel had a prefix-stripping ability.

With src-based layouts being common, I think it makes sense to update the example to show how to transform it into the desired wheel output. (This same problem would occur for a repo with multiple sub-projects, too).

Prompt:

```
Act as an expert in Sphinx, MyST, rules_python, Starlark, Bazel.

Update the py_wheel how to guide to show how to transform files using a src-layout.

Use the py_wheel.strip_path_prefixes arg to do this.
```

找到 py_wheel 操作指南，并检查其中针对基于 src 的布局的当前示例。使用文档中记录的 py_wheel.strip_path_prefixes 参数，展示转换为所需 wheel 输出的过程；当指南清楚地演示出最终布局时即完成。

由索引模型根据 Issue 内容生成。