Now that GitHub has a CI system, you can create a scheduled workflow to run once a week or something, and if you can package the feed discovery logic in a docker container, then you can run it in their CI pipeline and push the changes back to the repo

If you haven't already considered it, you can also likely push those files to a branch named gh-pages and GH will cheerfully serve them on https://alexyorke.github.io/oss_rss/libreoffice/all_torrent_... (although unlikely with the correct mime type :-( )