Crons Next.js auto-detection for Vercel does not work with App Router

[gaprl]

Is there an existing issue for this?

• [X] I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• [X] I have reviewed the documentation https://docs.sentry.io/
• [X] I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Sentry Saas (sentry.io)

Which SDK are you using?

@sentry/nextjs

SDK Version

7.110.1

Framework Version

No response

Link to Sentry event

No response

SDK Setup

No response

Steps to Reproduce

1. Create a route handler using the App Router as your job run.
2. Add a vercel.json file with a Cron job pointing to such route handler.
3. Deploy to Vercel

Expected Result

Monitor is created automatically in Sentry, and each Cron job execution is reported with it's appropriate status.

Actual Result

Nothing happens.

Auto-detection does work with Pages router, though.