SE is just a pile of questions. The frequently-asked ones are identified organically as people vote to close questions as duplicates of others.
That should be sufficient for this case. If these seem like they count as "Frequently Asked Questions" but aren't linked as duplicates, you can flag them for moderator attention with a message about the duplication.
Even if it wasn't redundant, we don't have any ability to create arbitrary pages like a dedicated FAQ. If we need a better way for people to discover frequently asked questions, we should submit a feature request for such a page/sidebar. (Right now the "similar questions" list that shows up when writing a question is the closest we have, and I believe that does draw on duplication data, but I've always thought it wasn't very effective as a "FAQ interface.")