Release v0.16.0

What's Changed

• feat: launch Gemini 3 in Gemini CLI 🚀🚀🚀 by @skeshive in https://github.com/google-gemini/gemini-cli/pull/13279

Full Changelog: https://github.com/google-gemini/gemini-cli/compare/v0.16.0-preview.5...v0.16.0