I don't think it has to do anything with UN and international sanctions, Iranians once negotiated in the Obama's presidency and made a deal with 5+1, after Obama, Trump broke the deal and the US is out of that now, but the rest of the world didn't, so it is just US sanction not "International" or UN sanctions.

On the other hand, blocking Iranian GitHub accounts is helping to change Iran regime? Are Iranian GitHub Users developing nuclear bombs there?