the library is currently in use by Heroku/SalesForce to build deploy java apps (or something like that) https://github.com/heroku/java-buildpack/blob/master/go.mod
I wonder what sort of settlement you could get if you were to send them a lawyer for real.
The damages probably amount to $0. "Don't use this code, no seriously don't" isn't exactly an advertisement of the value it provide.
which doesn't even use go.
And they'd like you to even move away from that replacement to an ever newer replacement: https://github.com/heroku/buildpacks-jvm
This is why the GPL is more developer friendly than other licenses. If a business doesn't like the GPL you can offer to relicense your code, ... for money. And money is the restitution you seek when the license is violated.