We recently announced [1] that with upcoming FCOS, last major release of Fedora Atomic Host is Fedora 29. This patch (avilable in email attachment) contains changes in bodhi pungi config to build Fedora Atomic related content only till F29. Also, we shouldn't be needing robosignatory signing for Atomic Host rawhide  refs.

[1] https://lists.projectatomic.io/projectatomic-archives/atomic-devel/2019-February/msg00004.html