v2.2.0 planning

[AkihiroSuda]

I'll release nerdctl v2.2.0 right after the release of containerd v2.2.0 (ETA: 2025-11-05)
https://github.com/containerd/containerd/blob/main/RELEASES.md#current-state-of-containerd-releases

[AkihiroSuda]

Would be nice if we could have a minimal support for nerdbox:

• [macOS + erofs] nerdctl pull fails with failed to mount /private/var/lib/containerd/tmpmounts/containerd-mount4013524920: not implemented #4570
• [macOS + nerdbox] nerdctl run fails with not implemented #4571