Add `.github/workflows/cgroup2.yaml` for running Fedora on Vagrant on
GitHub Actions to test cgroup2 environment.

Only very basic smoke tests are executed, as Vagrant is too slow to run
the entire sonobuoy.

Relevant:
- kubernetes-sigs/kind PR 2017
- https://github.com/rootless-containers/usernetes/blob/v20210201.0/.github/workflows/main.yamlSigned-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>