(main) Do not prompt on configuration file update

When updating configuration file, apt by default prompt the user for the
action to perform. Since we are running in a non-interactive context,
skip these prompts:

• --force-confdef ensure the configuration file is replaced by a newer version in the package if the previous package default configuration file was not modified;
• --force-confold keep the configuration file as it is if it has been modified compared to the one shipped in the previous version of the package.