[Platform] DigitalOcean Gradient AI Platform support

[dfridrich]

As a huge fan of Digital Ocean I would appreciate Symfony AI to support also their solution Gradient AI Platform.

[chr-hertel]

This is very much welcome - I guess you could either give #1052 a try since Digital Ocean also uses the Completions API, that was originally designed by OpenAI or it maybe boils down to a separate bridge.

Contributions welcome! 🙌