Describe the bug

When using .repeat() on an IterableDataset, this error gets thrown. There is this thread that seems to imply the fix is trivial, but I don't know anything about this codebase, so I'm opening this issue rather than attempting to open a PR.

Steps to reproduce the bug

1. Create an IterableDataset.
2. Call .repeat(None) on it.
3. Wrap it in a pytorch DataLoader
4. Iterate over it.

Expected behavior

This should work normally.

Environment info

datasets: 3.5.0