Bump ai and markitdown-ts

Bumps [ai](https://github.com/vercel/ai) to 5.0.89 and updates ancestor dependency [markitdown-ts](https://github.com/dead8309/markitdown-ts). These dependencies need to be updated together.


Updates `ai` from 4.3.19 to 5.0.89
- [Release notes](https://github.com/vercel/ai/releases)
- [Changelog](https://github.com/vercel/ai/blob/main/CHANGELOG.md)
- [Commits](https://github.com/vercel/ai/compare/ai@4.3.19...ai@5.0.89)

Updates `markitdown-ts` from 0.0.5 to 0.0.7
- [Release notes](https://github.com/dead8309/markitdown-ts/releases)
- [Commits](dead8309/markitdown-ts@v0.0.5...v0.0.7)

---
updated-dependencies:
- dependency-name: ai
  dependency-version: 5.0.89
  dependency-type: indirect
- dependency-name: markitdown-ts
  dependency-version: 0.0.7
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]