I think it is related to changes in the core libraries, so this affects all scripting languages (even DSL), that is where I found the solution for Jython as well.
I’m not sure how the old syntax looked like, but it was something like this:
from core.actions import Exec
# Usual Jython helper decorators here @rule, @when, etc...
# The actual commandLine call was something like this:
Exec.executeCommandLine("python3 /etc/openhab/scripts/openhab.py", 10000)
Now you have to do it this way:
from core.actions import Exec
from java.time import Duration
Exec.executeCommandLine(Duration.ofSeconds(100), "python3", "/etc/openhab/scripts/openhab.py")
Notice that you now need to import the Duration class from java.time and the timeout is now in seconds, previously it was in milliseconds.
Also you need to seperate all parameters as a seperate parameter. Previously you could pass the whole command in one string. So basically where you had spaces in your command before, now you need to make it a seperate parameter.