`--per-page N` to get all students fails for large N

You can use the `--per-page` and `--page` flags of `clone student-repos` to pull more than 30 assignments per page and view other pages! Another user is also working on a `clone-all` option that should be coming soon!

_Originally posted by @RyanHecht in https://github.com/github/gh-classroom/issues/12#issuecomment-1719538429_

Sadly trying to get all pages for something over about 100 students fails with:

```sh
gh classroom clone student-repos --per-page 199 --directory /tmp/grading

HTTP 500: Server Error (https://api.github.com/assignments/.../accepted_assignments?page=1&per_page=199)
```

Is there any progress on a clone _and_ pull for all students?