ISBN Endpoint Not Redirecting to book with ISBN

### Evidence / Screenshot (if possible)

### Relevant url?

https://openlibrary.org/isbn/9783906484754

This book has that ISBN: https://openlibrary.org/books/OL32964770M/

### Steps to Reproduce

1. Go to above url

* Actual: 404 page
* Expected: Redirects to the book that has this ISBN.

### Details

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

This is annoying because I often use the ISBN url to quickly get to books by copying isbn and pasting it into the isbn url.

### Proposal & Constraints

### Related files

### Stakeholders

Start by reproducing https://openlibrary.org/isbn/9783906484754 and tracing the ISBN endpoint's lookup and redirect behavior. Compare the result with book OL32964770M and identify why the ISBN resolves to a 404. Done means the endpoint redirects to the matching book and the behavior is covered by an appropriate test.

Written by the indexing model from the issue text.