GitHub Actions: use "larger" runners for nested virt

[AkihiroSuda]

kind/.github/workflows/cgroup2.yaml

Lines 16 to 18 in ac28d7f

	name: Cgroup v2
	# nested virtualization is only available on macOS hosts
	runs-on: macos-12

The current CI uses very slow macos-12 instances for nested virtualization, but the CI can get better performance and stability by switching it to "larger" Linux runners such as ubuntu-latest-4-cores: https://github.blog/changelog/2022-10-20-github-actions-larger-hosted-runners-are-now-automatically-created-for-customers/

CNCF projects have accesses to larger instances, but it has to be explicitly enabled by an admin of https://github.com/kubernetes-sigs :

• Open https://github.com/organizations/kubernetes-sigs/settings/actions/runner-groups
• Click Default Larger Runners
• Click Allow public repositories
• Click Selected repositories, and choose the kind repo

[AkihiroSuda]

(For cgroup v2, we can just consider switching from the Fedora VM to the free ubuntu-22.04 instances, but having a test with Fedora VM still makes sense, as its LSM and root filesystem is different from Ubuntu)

[BenTheElder]

Thanks!
We'll have to make a request with https://github.com/kubernetes/org

[AkihiroSuda]

Thanks! We'll have to make a request with https://github.com/kubernetes/org

Thanks, made a request:

• REQUEST: GitHub Larger Runners for kubernetes-sigs/kind kubernetes/org#4490

[AkihiroSuda]

Standard runners now support nested virt:

• GitHub Actions: use Linux runners for nested virt #3484