docs: Fix various old/broken links
The only one I had to delete because of a 404 was this one, it seems it is not there at all for gtk 3.24: https://developer-old.gnome.org/gtk3/3.24/api-index-deprecated.html
The only one I had to delete because of a 404 was this one, it seems it is not there at all for gtk 3.24: https://developer-old.gnome.org/gtk3/3.24/api-index-deprecated.html