env/linux-ppc64/osuosl: remove old VMs from notes
env/linux-ppc64/osuosl: remove old VMs from notes

They've been returned to OSU OSL.

Updates golang/go#34830

Change-Id: Id9de0d5d819e20456312fdb5817c82d1da6f845c
Reviewed-on: https://go-review.googlesource.com/c/build/+/205459
Reviewed-by: Bryan C. Mills <1c8aad60184261ccede67f5c63a0d2a3bf3c9ff4@google.com>

golang/build,golang/build,golang/build,golang/build