I've created https://github.com/torproject/stem and a "stem-maintainers" team which has admin access (read, write, clone, add collaborators) to that repo. No one's in the group yet because I didn't know whom to add.
No prob! You should have an invite to the organisation and for admin permissions on the stem-maintainers team. I think that means you can add more contributors/members, but if not just ping me or another github admin with their usernames and I'll add them.
I ask because it seems easy for the github people to say "I dunno, the git.tpo folks need to take the next step" and for the git.tpo folks to say the opposite.
In particular, isis's comment above seems to imply that git.tpo needs to enable some mirroring thing?
But hiro just now said that without github permissions, there's nothing to do on the git.tpo side yet.
After chatting with atagar to confirm, this effort is done as far as I'm aware!
torproject-pusher is automatically sync'ing stem git.tpo -> GitHub, as well as auto-closing PRs / marking them as merged.
If something's not done/ready here, please feel free to re-open.