in version 1.51.1, custom request header attributes do not support Chinese.

[reproduction](https://stackblitz.com/edit/3uf8e7nx?file=package.json,src%2Fdemo.vue)

<img width="3394" height="1574" alt="Image" src="https://github.com/user-attachments/assets/deeaf308-0fc9-4103-93de-7323c7438597" />