Due to an unknown bug we never previously distributed the generated
modules-resources.{c,h} files. This bug was apparently fixed in commit
e80ff833. However, this adds about 20%
to the size of the source archive. Since we effectively required
glib-compile-resources for building GJS by not previously distributing
those files, we may as well save some download bandwidth by not
including any generated GResource files.

Unreviewed, pushing in order to be able to release without making the
archive much larger.