Make use of auto-apt-proxy to use local proxy.

roles/aptcacher/tasks/main.yml

@@ -1,17 +1,10 @@
 - name: install apt-cacher-ng package
   apt:
-    name: apt-cacher-ng
+    name:
+      - apt-cacher-ng
+      - auto-apt-proxy
     state: latest # noqa package-latest
 
-- name: enable apt-cacher-ng for localhost
-  copy:
-    src: apt.conf
-    dest: /etc/apt/apt.conf
-    force: false
-    mode: 0644
-  notify: "start apt-cacher-ng"
-  when: not run_in_installer|default(false)|bool  ## do not enable apt-cacher during installation
-
 - name: check if preseeded installer is available
   stat: path={{ tftp_root }}/d-i/{{ di_dist }}/preseed.cfg
   register: preseedcfg