Close [AI-59](https://linear.app/affine-design/issue/AI-59)
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Added support for two new providers, Anthropic and Exa, in test environments and configurations.
- **Chores**
- Updated workflow and test environment setup to include API keys for Anthropic and Exa providers.
- **Refactor**
- Changed the AI model used for the "Chat With AFFiNE AI" prompt to "claude-3-7-sonnet-20250219".
<!-- end of auto-generated comment: release notes by coderabbit.ai -->