Running the Windows version in Wine probably would never have occurred to me.
Arch (i UsE aRcH bY tHe WaY)'s AUR has a package for it. I just installed gpaint on a Raspberry Pi 4 just to see if it worked. It worked perfectly. (Disclaimer: I did have to update the architecture in the PKGBUILD to allow armv7h, but on an x86_64 machine, that wouldn’t be an issue.)
You could probably run Arch in Docker and install the AUR package in the Docker container if you wanted to go that route.