"Font family 'Futura' not found" on introduction page

Under [Publication ready plots](https://plotnine.org/guide/introduction.html#publication-ready-plots), there is a 

```
findfont: Font family 'Futura' not found.
```

error.

<img width="800" alt="Screenshot of documentation page" src="https://github.com/user-attachments/assets/efed8743-99a0-43cf-b028-b331f89d29d8" />