debian-repo: add unzip to unzip gitlab CI artifacts

debian-repository/tasks/main.yml

 ---
-# file: debian-repository/tasks/main.yml
-#
+
 - name: ensure we have the packaging software installed
   apt:
-    name: ["reprepro", "rssh"]
+    name:
+      - reprepro
+      - rssh
+      - unzip
     state: present
   tags:
     - packages