Hi, I did this exact thing just a week ago (no Cyberdeck, but a Raspberry Pi 5). Once you have Godot installed on the Pi, simply copy over your project folder from your other machine (via thumb drive, cloud service, or whatever). Then on the Pi, once you open Godot, it should give you a list of projects. DO NOT WORRY IF YOUR PROJECTS DON’T SHOW UP. In that case, simply click “import” near the top left of the Godot initial screen, and tell it where in the Pi you put the project folder. It really is that simple. My projects ran just fine (admittedly I’m new to Godot so it’s just simple projects, not sure if anything needs to change for something more complex).
If you have trouble initially getting Godot to run properly on the Pi 5 at all (even on a new project), rest assured it really is possible and easy (at least for Godot v 4.7.2). The problem is that the official Godot docs don’t always specify every last dependency you need for the arm/pi system. So if it doesn’t work, you may be missing dependencies. You should not have to compile Godot from source (I tried that, but it wasn’t the problem - the dependencies were, and once I solved that, I could use the official pre-built arm binary). If you get stuck, refer to Godot 4.x on the Raspberry Pi and/or ask on that thread (or on here and I can help)