cgroup2: cpu controller is delegated by default since 2022

[AkihiroSuda]

rootlesscontaine.rs/content/getting-started/common/cgroup2.md

Lines 46 to 50 in 559f944

	By default, a non-root user can only get `memory` controller and `pids` controller to be delegated.
	```console
	$ cat /sys/fs/cgroup/user.slice/user-$(id -u).slice/user@$(id -u).service/cgroup.controllers
	memory pids
	```

systemd/systemd@b8df7f8

The cpu controller seems enabled by default for systemd >= 252 (Ubuntu >= 23.04 , Debian >= 12, RHEL >= 9, ...)

• feat: Clarify Rootless Runtime Requirements kubernetes-sigs/kind#4022 (comment)