`extra-build-dependencies` docs example is wrong

The example rendering for `extra-build-dependencies` is wrong at https://docs.astral.sh/uv/reference/settings/#extra-build-dependencies:

<img width="1063" height="670" alt="Image" src="https://github.com/user-attachments/assets/c932c14f-4752-4a48-b90f-21c7c7e691ec" />