Okay, I have found the section that you are referring to and have read the instructions.
I run WordPress on an eleven-year-old Macintosh G4 mini-tower running Tiger 10.4.11.
Tiger 10.4.11 uses launchd to run automated cron jobs.
I have absolutely no experience with using launchd or with setting up and running cron jobs.
While I do know that they require setting up a .plist file and/or a shell script, I haven't been able to fully understand exactly how to do this, even though I have read and studied online documentation regarding launchd. I am a bit on the older side, and these things don't come to me that easily.
If someone would be willing to write this plist file or shell script for me, I would be most appreciative. I can provide you with the path for the cloner.cron.php file on my server, as well as the path for my custom-installed PHP binary.
Thanks to whoever may come to my assistance.