Loading message displays on list carousel when nothing left to load

Loading... displays on list carousel even when there are no remaining works to load.
### Evidence / Screenshot (if possible)

### Relevant url?
https://openlibrary.org/collections/challenged-goddard-school-district

### Steps to Reproduce

1. Go to https://openlibrary.org/collections/challenged-goddard-school-district
2. Resize the window so that the blue left/right arrow buttons appear on the carousels
3. Go right until the end.

* Actual: Loading...
* Expected: No loading message as all works are already displayed.

### Details

- **Logged in (Y/N)?**
- **Browser type/version?**
- **Operating system?**
- **Environment (prod/dev/local)?** prod

### Proposal & Constraints

### Related files

### Stakeholders

@mekarpeles