chore(deps-dev): bump @slidev/cli from 0.50.0 to 0.51.0-beta.4 (#269)

Bumps [@slidev/cli](https://github.com/slidevjs/slidev) from 0.50.0 to 0.51.0-beta.4.
- [Release notes](https://github.com/slidevjs/slidev/releases)
- [Commits](slidevjs/slidev@v0.50.0...v0.51.0-beta.4)

---
updated-dependencies:
- dependency-name: "@slidev/cli"
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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