DroneCAN/UAVCAN: firmware update of CubeNodETH fails

While it is possible to use MP to update the Here4 GPS and HereFlow firmware, it is **not** possible to update the firmware on the **CubeNodeETH**

The procedure should be:

1. Connect to the Autopilot
2. Setup, Optional Hardware, DroneCAN/UAVCAN
3. Select "MAVLinkCAN1" or "MAVLinkCAN2" depending upon which can port the CubeNodeETH is connected to and press "Connect"
4. The CubeNoteETH should appear in the list as "org.ardupilot.CubePilot-PPGW" and "SW Version" = "2.0.0"
5. Select "Menu" and "Update" or "Update Beta"
6. When "Search from the Internet" appear press "yes"

The window below appears but never completes

I think it is quite important that users be able to update the firmware on the CubeNodeETH because I strongly suspect that there is a performance issue with the firmware shipped from the factor. See this issue: https://github.com/ArduPilot/ardupilot/issues/29673

Reproduce the failure using the listed Mission Planner DroneCAN/UAVCAN connection and CubeNodeETH update steps. Trace the firmware update flow from the DroneCAN/UAVCAN hardware screen, then identify the relevant tests or entry points, if present. Done means the CubeNodeETH update completes instead of leaving the progress window stuck.

Written by the indexing model from the issue text.