build(deps): bump authlib in /solutions/enterprise-ai-agent

Bumps [authlib](https://github.com/authlib/authlib) from 1.6.8 to 1.6.9.
- [Release notes](https://github.com/authlib/authlib/releases)
- [Changelog](https://github.com/authlib/authlib/blob/main/docs/changelog.rst)
- [Commits](authlib/authlib@v1.6.8...v1.6.9)

---
updated-dependencies:
- dependency-name: authlib
  dependency-version: 1.6.9
  dependency-type: indirect
...

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Author: dependabot[bot]