How can I execute sudo commands as a cron job?
Cron is not in any way deprecated, but LaunchD has more versatility and is used, and actively maintained/supported by Apple.  Their best practices guide is here

LaunchDaemon jobs(versus LaunchAgents, which take on a users id) run in root's context without needing to enable the root user. All that is required is a properly formed XML file(you can just copy-paste pre-existing ones in /Library/LaunchDaemons, substituting your script for the ProgramArguments with the applicable schedule keys) with the proper ownership/permissions.  An older writeup can be found here:
afp548's launchd-in-depth article