chore: bump node-fetch in /packages/docsify-server-renderer

Bumps [node-fetch](https://github.com/node-fetch/node-fetch) from 2.6.6 to 2.6.7.
- [Release notes](https://github.com/node-fetch/node-fetch/releases)
- [Commits](node-fetch/node-fetch@v2.6.6...v2.6.7)

---
updated-dependencies:
- dependency-name: node-fetch
  dependency-type: direct:production
...

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