Moving from Go module v4 to v5 prepares us for public releases.
Move done using gomove [1] as with the v3 and v4 moves.
[1] https://github.com/KSubedi/gomove
Signed-off-by: Matt Heon <mheon@redhat.com>
This moves the cgroup code to pod_internal_linux.go and adds a no-op
stub for FreeBSD.
[NO NEW TESTS NEEDED]
Signed-off-by: Doug Rabson <dfr@rabson.org>