cgroup support no longer working on Linux 5.15

[fhunleth]

It might be broken on an earlier version of Linux, but this is the first version that I've seen it.

There are a couple issues. First, the unit tests don't recognize when the group as been created. Once you fix that, there are many more errors, so something is clearly different now.

[TwistingTwists]

+1

I updated the linux to 6.8 and I have more than 17 zombie processes when launching them via MutonTrap.cmd