As noticed by marina on static pages where Moodle's PHP is not involved such as https://moodle.org/TRADEMARK.txt an outdated favicon image is shown.

This is controlled by an nginx rewrite rule:

build/default.conf:    rewrite ^/favicon\.ico$ /local/moodleorg/top/favicon.ico break;

Let's make sure that each community site still shows the correct favicon even on static pages. Probably by having them all in that location and picking the appropriate one in each site's config.