Raise yum-cron-hourly random_sleep to 60m

[evan-goode]

For https://issues.redhat.com/browse/RHEL-40868.

Spreads out the load more on mirror servers.

[evan-goode]

Ideally, the random delay would be 60 minutes, so mirrors see a uniform distribution across the whole hour. For dnf-makecache.timer, we already use a 0--60 minute random delay.

Initially I was hesitant about increasing random_sleep to 60 minutes, since cron would be much more likely to start another yum-cron when a process is already running. But upon checking /etc/cron.hourly/0yum-hourly.cron, there is a locking mechanism that prevents this from happening:

# Only run if this flag is set. The flag is created by the yum-cron init
# script when the service is started -- this allows one to use chkconfig and
# the standard "service stop|start" commands to enable or disable yum-cron.
if [[ ! -f /var/lock/subsys/yum-cron ]]; then
  exit 0
fi

so I think a 60 minute random_sleep would be fine. In a "worst-case" scenario, cron runs yum-cron on the hour at 00:00, yum-cron random_sleeps 59 minutes and runs from 00:59--01:01, then cron skips running yum_cron at 01:00 since the first process has not released the lockfile. The next yum_cron would be started at 02:00 and could sleep until 02:59.

This situation is already possible in the status quo, but now it could happen even for short-running yum-cron tasks like makecache. I think this is a reasonable tradeoff, given that this patch would lighten mirror loads and avoid making too many changes to the yum-cron scheduling logic.