debian-updates: add installation of dependencies

debian-updates/tasks/main.yml

 ---
 # file: supplemental/debian-updates/tasks/main.yml
 
+- name: ensure any dependencies are available
+  apt:
+    name: python3
+    state: installed
+  tags:
+    - debian-updates
+
 - name: ensure the deploy key is available
   copy:
     src: "{{ debupdates_deploy_key }}"