2FA enforcement in the org

[webknjaz]

@aio-libs/admins @aio-libs/aiohttp-dev @aio-libs/triagers

I'd like to start enforcing 2FA in @aio-libs. I checked and there's only 7 human org members (and 1 bots), plus, 2 outside collaborators (and another bot) that don't have it on. All exhibit low or no activity over the past years, so they present a security risk.
Among those, 1 bot and 2 humans have restricted accounts because GitHub enforces 2FA for them, and they didn't follow through.

[webknjaz]

The 2FA enforcement is now set up.