A small update that moves the save folder from:
%appdata%\\Godot\\app_userdata\\Bush 1022\\saves_v2 on Windows
~/.local/share/godot/app_userdata/Bush 1022/saves_v2 on Linux
to the "saves" folder in the game's install directory. You can copy your old saves there and they should work with Steam Cloud Saves across platforms.
The game should now be able to sync saves between a Steam Deck and a Windows PC.