Disable a specific key on a specific keyboard

I suspect this can't be done, but I would like to disable a specific key (namely '6' on the top row) on a specific keyboard (namely my laptop internal keyboard). The key is spamming 6s but is otherwise working (and I've ordered a replacement but it will take a long time due to location). I am mostly using a USB keyboard but it is a pain to disable an entire keyboard (using xinput --float) just for one key. So: is it possible to disable a specific key on a specific keyboard? I am using Kubuntu 19.10 although I suspect that is not important for this.