[CI] Fix the Build Preview Site Workflow

[rishiraj38]

Fix the build preview site workflow so that preview builds complete successfully and the generated preview site is deployed correctly.

Environment

• Host OS: Mac Linux Windows
• Platform: Docker or Kubernetes
• Meshery Server Version: stable-v
• Meshery Client Version: stable-v

---

Contributor Guides and Resources

• 🛠 Meshery Build & Release Strategy
• 📚 Instructions for contributing to documentation
  • Meshery documentation site and source
• 🎨 Wireframes and designs for Layer5 site in Figma (open invite)
• 🙋🏾🙋🏼 Questions: Layer5 Discussion Forum and Layer5 Community Slack