Why I did it
Update smartmontool verson to 7.4. This is done to prevent smartmontools service to exit with non-zero exit status on platform that does not have a SSD/disk to be monitored.
Until Debian Bullseye (which had smartmontools 7.2), Debian had a patch applied that changed the default quit mode to never exit. A bug report was filed on Debian, saying that the source code patch isn't needed and could just be done via command line options, and also that smartmontools 7.3 has a new built-in option to exit with 0 if there are no monitorable devices found (which prevents systemd from treating it as a service failure). Because of that, Debian Bookworm (which also upgraded to 7.3) removed the patch and restored the default behavior of exiting with exit code 17 if there are no devices found.
Smartmontools v7.3 has this issue, because of which smartd exits with non-zero exit status even with "-q" option.
How I did it
Update the smartmontools to version 7.4 which has the fix for exiting gracefully if no monitoring device is found
Added smartd option "-q nodev0" to allow smartd to exit with status 0 if no monitoring device found