The difference was that the russian government did actively attack them, it merely was trying to block illegal content. Github didn't remove the repo, they simply blocked that page for russian users. Also the material they were blocking was a suicide poem, and while free speech was being minorly impacted, all in all it's removal didn't affect very many people.

In this case china is attacking them directly, and removing the repos in question would affect people's ability to use that software, greatly affecting freedom from censorship for many many people.