refactor: Update apt-cacher setup script to use apt-cacher.local as the proxy server

apt-cacher/setup.sh

@@ -1,2 +1,2 @@
 #!/bin/bash
-apt install squid-deb-proxy-client
+echo 'Acquire::http { Proxy "http://apt-cacher.local:3142"; }' | sudo tee -a /etc/apt/apt.conf.d/proxy