Description of problem:

$ dnf remove watchdog
...
Running transaction
  Preparing        :                                                                                              1/1 
  Running scriptlet: watchdog-5.16-2.el9.x86_64                                                                   1/1 
Failed to disable unit: Unit file watchdog.ping.service does not exist.

  Erasing          : watchdog-5.16-2.el9.x86_64                                                                   1/1 
  Running scriptlet: watchdog-5.16-2.el9.x86_64                                                                   1/1 
  Verifying        : watchdog-5.16-2.el9.x86_64                                                                   1/1 
Installed products updated.


This is likely caused by a typo in preuninstall:

    if [ -d /run/systemd/system ]; then 
          /usr/bin/systemctl --no-reload disable --now watchdog.ping.service || : 
    else 
          /usr/bin/systemctl --no-reload disable watchdog.ping.service || : 
    fi 


The service name is watchdog-ping, not watchdog.ping :

$ rpm -qlp watchdog-5.16-2.el9.x86_64.rpm | grep service
/usr/lib/systemd/system/watchdog-ping.service
/usr/lib/systemd/system/watchdog.service


Version-Release number of selected component (if applicable):
watchdog-5.16-2.el9