copr-backend: put rpkg into latest-version packages list

roles/copr/backend/files/provision/provision_builder_tasks.yml

@@ -1,4 +1,4 @@
-- name: put temporary fedora repos into yum.repos.d
+- name: put infra repos into yum.repos.d
   copy: src=files/dnf/{{ ansible_architecture }}/{{ item }} dest=/etc/yum.repos.d
   with_items:
     - infra-tags.repo
@@ -46,6 +46,7 @@
     - mock
     - dnf
     - copr-rpmbuild
+    - rpkg
 
 - name: put updated mock configs into /etc/mock
   template: src=files/mock/{{ item }} dest=/etc/mock