Fix missing parens in requireAuth()

[SuperSection]

Correction in the naming of requireAuth() which was written as requireAuth) under the section of "requireAuth usage changes" in .

🔎 Previews:
The Page where I noticed the typo: Upgrade from Clerk's Node SDK to the Express SDK
I have attached image of the section where I made changes.

Explanation:

• It's Just a typo error correction, from requireAuth) requireAuth().
• It maintains fluency while reading the docs. Not solving much problem but rather any user reading that portion will not stumble across that noticeable error in parentheses.

This PR:

• Corrects the format of the name requireAuth) to requireAuth()

Checklist

• [ ✅] I have clicked on "Files changed" and performed a thorough self-review
• [✅ ] I have added the "deploy-preview" label and added the preview link(s) to this PR description
• [ ✅] All existing checks pass

[victoriaxyz]

Thank you for your contribution to Clerk Docs! :)