Add crons support to Next.js SDK for Vercel

[HazAT]

### Tasks
- [ ] https://github.com/getsentry/sentry-javascript/pull/8084
- [ ] https://github.com/getsentry/sentry-javascript/pull/8088
- [ ] https://github.com/getsentry/sentry-docs/pull/6903