fix: deduplicated body tags

[huang-julien]

🔗 Linked issue

• fix feat: allow tags insertion before </body> #67

❓ Type of change

• 📖 Documentation (updates to the documentation or readme)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

• fix body tags (unexpected deduplicated scripts)
  • fix body tags being removed then replaced on updateDOM
  • fix deduplicated body tags on ssr

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.