Update Sentry example readme to mention Next.js 12 support (#32724)
Update Sentry example readme to mention Next.js 12 support (#32724)

@sentry/nextjs support has changed as it now supports version from 10.0.8 also meaning they support Next.Js 12

## Documentation / Examples

- [x] Make sure the linting passes by running `yarn lint`


Co-authored-by: JJ Kasper <fbae0e752deb2c0fed663fa6dec6c97ee2546cfe@users.noreply.github.com>
azukaru/next.js,azukaru/next.js,azukaru/next.js,zeit/next.js,azukaru/next.js,JeromeFitz/next.js,JeromeFitz/next.js,JeromeFitz/next.js,zeit/next.js,zeit/next.js,JeromeFitz/next.js