GitHub pull requests exist as revisions in your repository. There are APIs for fetching nearly everything and the CLI tool for working with their API is pretty nice.
Gerrit is dramatically nicer for code review and great that it's all stored as notes in the repository.
We use GitHub primarily primarily for the low barrier to entry for people reporting issues or making small changes, especially since we have our websites and documentation in public Git repositories. Wouldn't care as much if we only had to be accessible to experienced developers.
I doubt GitHub is banning anyone for being Russian or speaking Russian. The people who were banned likely worked at an explicitly sanctioned company. They likely banned accounts using same IPs once they found some of their accounts and then confirmed it wasn't a VPN or something.
That's the commit whose pull was requested. The PR is the associated opening request text, comments, reviews, history of changes to what is the requested commit to pull, etc.