fix: await sendRedirect in auth handler

[DavidDeSloovere]

🔗 Linked issue

nuxt-modules/i18n#2980

❓ Type of change

• 📖 Documentation (updates to the documentation, readme or JSdoc annotations)
• 🐞 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)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

sendRedirect returns a promise and should be awaited

I have nuxt i18n that sets a cookie, but there is a conflict if await is not used.

I have patched this locally and the cookie specific error was gone.

📝 Checklist

• I have linked an issue or discussion.
• I have added tests (if possible).
• I have updated the documentation accordingly.