How to categorize this issue?

/area open-source
/kind enhancement

What would you like to be added:
With #5255 we have switched the cgroup driver from cgroupfs to systemd for shoots >= 1.23. However, this change was reverted with #5324.

Let's look into that the consequences of this change are, how the container runtime needs to be configured and how to properly roll this out.

Why is this needed:
Following upstream recommendations.

Work Items

• Switch default kubelet configuration to systemd for all k8s versions >= 1.24 as was done in https://github.com/gardener/gardener/pull/5255/files#diff-fc4776dd3fd3277fcbaac11c0bcfe15e6bd797038eb1cc601444de5ca4c3bc68 but later reverted
  • We don't care about docker configuration as that's not a possible configuration in Gardener for k8s >= 1.23
• Introduce a property/helper function to figure out what the cgroupfs driver configuration is
• Switch g/g containerd configuration to respect the selected cgroupfs driver

• Adapt containerd bootstrapping in OS extensions to use systemd as cgroupfs driver
  • Pass in an additional parameter similar to isContainerDEnabled that indicates which cgroupfs driver is used.
  • Gardenlinux
  • Flatcar
  • Ubuntu
  • SUSE Chost

Open Questions

• How do we prevent running with systemd as cgroupfs driver when the OS extensions have not been updated to respect this in their bootstrapping logic?
• Should we have a killswitch e.g. in cloud-config/kubelet reconfiguration that throws and error when there's a mismatch between kubelet config and containerruntime?