Author of this issue from April 2025 says:

Since the repository wasn’t updated in about 5 years, I suppose that the extension is no longer open source, correct? But since I still see new releases on the Chrome/Firefox stores, can we just have this GitHub repository [archived] then?

The tracking protection list is regularly updated so it’s possible new releases on stores are a result of building the code with the newer list I suppose. Does anyone know for sure? There have been no comments on that issue.