earthly: Some DIND scenarios fail when using cgroups v2

Notable, podman and kind have been documented to fail on systems using cgroups v2. Here is all the relevant information:

• Docker updated to use cgroups v2 in Docker Desktop at version 4.3.0. I do not know what docker CLI version this correlates to
• Our unit tests that use podman appear to be trying to use cgroups v1. We may need to update podman for these unit tests since docker is on v2 (and podman is inside docker here, for our unit tests), or add compatibility flags
• To turn off/on cgroups v2, I use the following kernel param: systemd.unified_cgroup_hierarchy=0 (Pop!_OS 21.10)
• v2 is a unified, single-root hierarchy; vs the v1 multi-root approach
• You can examine currently running cgroups via systemd-cgtop
• kind also does not run when using v2, inside a WITH DOCKER. I haven’t dug too much into regular docker, but I assume its only partially functional in this case
• You can check what cgroups versions you have by grep cgroup /proc/filesystems