Donation link is 404 for many apps
I suppose this is not really an Apps for GNOME bug, but the page makes it more visible than before.
The donation link for many of the apps on the page lead to a 404, see for example on https://world.pages.gitlab.gnome.org/apps-for-gnome/en/app/org.gnome.Boxes/
Looking at the cause for this, it seems many packages list http://www.gnome.org/friends/ as donation link in their appdata file. That link however now just shows a 404 page. I assume this will need to be replaced with https://www.gnome.org/donate/