Because the command line is wp-cron.php you’d either have to ignore something like
cmd:/usr/bin/php /home/*/public_html/wp-cron.php (which is probably bad since it’ll stop notifications on every script running with wp-cron) OR check out the Uptime in your notifications and set PT_LIMIT to something higher. You may still get some notifications, but they’ll be a lot less.
CSF states the following with the PT_LIMIT:
“The following is the number of seconds a process has to be active before it
is inspected. If you set this time too low, then you will likely trigger
false-positives with CGI or PHP scripts.”