[dev-overlay] use absolute font src url (#76229)
Fix font loading from a non-root URL:
Repro:
```
pnpm next dev test/development/app-dir/owner-stack/
```
and Visit http://localhost:3000/browser/uncaught
Shows
```
GET /browser/__nextjs_font/geist-latin.woff2 404 in 330ms
```
