chore(deps): bump @ai-sdk/openai in /legacy/typescript

Bumps [@ai-sdk/openai](https://github.com/vercel/ai/tree/HEAD/packages/openai) from 3.0.39 to 3.0.64.
- [Release notes](https://github.com/vercel/ai/releases)
- [Changelog](https://github.com/vercel/ai/blob/@ai-sdk/openai@3.0.64/packages/openai/CHANGELOG.md)
- [Commits](https://github.com/vercel/ai/commits/@ai-sdk/openai@3.0.64/packages/openai)

---
updated-dependencies:
- dependency-name: "@ai-sdk/openai"
  dependency-version: 3.0.64
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Author: dependabot[bot]