Works sometimes show up twice in a QueryCarousel that calls a subject tag

In the [LGBTQ collection](https://openlibrary.org/collections/LGBTQ), we're using QueryCarousels searching by subject. Sometimes a work will show up twice in the results. This has happened more than once in different, unrelated carousels.

### Evidence / Screenshot (if possible)


### Relevant url?

https://openlibrary.org/collections/LGBTQ

### Steps to Reproduce

1. Go to the [LGBTQ collection](https://openlibrary.org/collections/LGBTQ).
2. Wait 10+ seconds for the page to load. If this bothers you, please see #5728.
2. Scroll down to the [LGBTQ sociology carousel](https://openlibrary.org/collections/LGBTQ#lgbtq_sociology).
3. Click the right arrow to "load more" three times.

* Actual: The work Spirit in the Flesh shows up twice, but links to the same work id. It appears to be a total duplicate.
* Expected: The work Spirit in the Flesh should only show up once.

### Details

- **Logged in (Y/N)?** both
- **Browser type/version?** Firefox 91.0.2 for Mint
- **Operating system?** Linux Mint 20
- **Environment (prod/dev/local)?** prod, testing

### Proposal & Constraints

It's possible this was two works that were both given the LGBTQ sociology subject separately, then merged later? I'm not sure.

Is it possible to have the macro do a uniqueness check on work ids before returning the results?

### Related files

### Stakeholders
@libjenner