test(create-next-app): use latest examples (#24048)
test(create-next-app): use latest examples (#24048)

Update CNA test suite to consume [vercel-learn-starter](https://github.com/vercel/next-learn-starter) as the example repo.

## Bug

- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added

## Feature

- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.

## Documentation / Examples

- [ ] Make sure the linting passes

JeromeFitz/next.js,azukaru/next.js,flybayer/next.js,zeit/next.js,JeromeFitz/next.js,flybayer/next.js,azukaru/next.js,flybayer/next.js,zeit/next.js,JeromeFitz/next.js,azukaru/next.js,azukaru/next.js,flybayer/next.js,zeit/next.js,JeromeFitz/next.js