Nothing much as I'm not sure how to start up and keep the stream running. I've confirmed the camera is up and running and working via the libcamera module.
Systeminfo Bundle
You can download this in OctoPrint's System Information dialog ... no bundle, no support!)
OctoPrint doesn't directly interface with the camera, it just uses the stream and/or snapshot URLs provided by the camera software.
The OctoPi images provide the OS, the camera software, and OctoPrint all nicely bundled together. There are currently two OctoPi images available, one of which has new camera software (and a new interface).
You are not using an OctoPi image. You didn't mention how you installed OctoPrint but I am assuming you used octoprint_deploy. It has some camera streamer support but I'm not sure if it works with the PiCams.
I'm not a camera expert but I'm guessing that while libcamera provides part of the software support for the camera, there may be a need for a streaming application to provide what OctoPrint needs.