This reverts commit a268288.

cgroups need to be managed by the worker itself - worker is unable to add its own PID into the child cgroup due to a violation of the cgroupv2 common ancestor rule. Workaround will be as follows:

• The worker will manage its own cgroups like before.
• We will use systemd to get a user delegated space for creating/managing cgroups by default, with the option of configuring a custom pool path (user will be responsible for making sure the custom path meets all the requirements for the worker to function)