Confirm published preprints are excluded

[vot]

We don't want to include in the listing any preprints that have already been published as a peer-reviewed version (because they don't need more attention on the preprint version).

Rich Abdill:
We should be able to identify these, as follows:
The article_publications table includes most of the preprints that have been flagged in bioRxiv as published.
The article field is the ID from the articles table, and the doi field is the published DOI.
Fraser et al (https://doi.org/10.1101/673665) found these were pretty reliably detected, but it's complicated."

I'm not sure if this rule applies already for the tool.

Please confirm if so or not, and if not, please reply here with any info on how to resolve this (including whether you've capacity or request someone else to do this; no obligations!)