I'm not a licensed Nintendo developer but off of my knowledge from the Wii U era...

The Godot game engine cannot include any of the Nintendo Switch SDK nor can your game include any of the Nintendo Switch SDK or APIs unless you are a registered Nintendo developer and have signed their NDA. You cannot share any of Nintendos proprietary code or information.

So you could share your source code for a Switch game, minus any code or SDKs specific to the Switch.