Stable diffusion model fails on Mac: WebNN backend does not support data type: uint8

<img width="1668" height="846" alt="Image" src="https://github.com/user-attachments/assets/ed8b2957-cfda-4651-b18f-9ac181660093" />
<img width="1003" height="403" alt="Image" src="https://github.com/user-attachments/assets/d8f43e96-804d-4502-87cc-a868c4bdd8b3" />

device: Apple M3 Pro
macOS: 15.6.1
chrome: 145.0.7630.0