It was forked to build the 5.17 pre-release, which is not needed
anymore. Remove now to unclutter pmaports, and to get pretty much all
remaining packages for x86_64 out of the queue on
build.postmarketos.org.
postmarketos-ui-plasma-mobile has !armhf in its arches list, so it does
not make sense to build these packages for armhf either. Let's save some
building time.
[ci:skip-vercheck], [ci:skip-build]
