Plugin not compatible with check_mk 2.3 - factory_settings not defined

[randomcop]

Hi.

The plugin check_mk_zvolsize does not run on CMK Version 2.3 raw
Very sad, as it is very useful for monitoring zvol storage based bhyve-VMs on FreeBSD.

My Check_MK Version: check-mk-raw-2.3.0p14
/omd/sites/mysite/bin/python3.12
Description:	Ubuntu 24.04.1 LTS
Release:	24.04
Codename:	noble

OMD[mysite]:~$ mkp list

zvolsize               1.1     ZVol Sizes                         Jens Giessmann jg@handcode.de                                             1.2.6p12     None          4     Enabled (active on this site)

OMD[mysite]:~$ cmk -D lemmy
Ignoring outdated plugin file /omd/sites/mysite/local/share/check_mk/checks/zvolsize: name 'factory_settings' is not defined -- this API is deprecated!

I looked into /omd/sites/mysite/local/share/check_mk/checks/zvolsize,
factory_settings seems to be defined?

# default values for warn_used, crit_used, warn_snap, crit_snap
# zvolsize_default_values = (1.5,2,0.5,1.0)
factory_settings["zvolsize_default_values"] = {
   "levels" : (1.5,2,0.5,1.0)
}

https://docs.checkmk.com/latest/en/dev_guidelines.html

3. Constructing a check plug-in
3.1. General structure
"Default values for the check parameters (factory_settings)."

4.6. Default thresholds
"The default thresholds should be defined in factory_settings (if the check has a dictionary as a parameter)."

Any ideas why it does not work?

Regards,
Kai.