Edition download options have broken links b/c file not yet generated

### Problem

For Internet Archive items where there _are_ valid download options, e.g. HOCR, there are sometimes not DAISY or EPUB files. They can be generated on the fly, but they have not been pre-derived. When specific download format (e.g. EPUB) has not been pre-derived (but is otherwise derivable or able to be made on the fly), the Edition page shows broken links.

See, e.g.: https://archive.org/details/sierraclubbullet1196sier/

However, the corresponding Edition has broken links for `ePub` and `DAISY`, under Download Options, because neither file format has been created in the Internet Archive item: https://openlibrary.org/books/OL25496907M/Sierra_Club_bulletin.

#### Evidence / Screenshot

#### Relevant URL(s)
- https://archive.org/details/sierraclubbullet1196sier
- https://openlibrary.org/books/OL25496907M/Sierra_Club_bulletin

### Reproducing the bug

1. Go to https://openlibrary.org/books/OL25496907M/Sierra_Club_bulletin
2. Click on `ePub` or `DAISY` under the download options.

* Expected behavior: The file gets generated.
* Actual behavior: The file does not get generated, and the patron is notified about the generation.

### Context

- Browser (Chrome, Safari, Firefox, etc):
- OS (Windows, Mac, etc):
- Logged in (Y/N): Y
- Environment (prod, dev, local): prod

### Notes from this Issue's Lead

#### Proposal & constraints

#### Related files

#### Stakeholders

#### Instructions for Contributors

This will need an associated issue on the Internet Archive side most likely, somewhere.

- Please [run these commands](https://github.com/internetarchive/openlibrary/wiki/Git-Cheat-Sheet#working-on-your-branch) to ensure your repository is up to date **before** [creating a new branch](https://github.com/internetarchive/openlibrary/wiki/Git-Cheat-Sheet#making-changes-and-creating-a-pull-request) to work on this issue and **each time after** pushing code to Github, because the pre-commit bot may add commits to your PRs upstream.

Start by reproducing the ePub and DAISY links from the Sierra Club bulletin Edition page and trace how its Download Options are assembled. Determine where Open Library decides whether a format is available and how generation is requested, while checking the stated Internet Archive dependency. Done means derivable formats no longer show broken links and the expected file-generation behavior is preserved.

Written by the indexing model from the issue text.