v0.2.8

Corresponding to Llama Stack Release v0.2.8

What's Changed

• Sync chat completion list/retrieve APIs by @ehhuang in #21
• Sync updates from stainless branch: ehhuang/dev by @ehhuang in #22

New Contributors

• @ehhuang made their first contribution in #21

Full Changelog: v0.2.7...v0.2.8