cheetah: drop unused package

This was imported long ago for a project now dead, and no one else
is using it.  Punt it since it's python2-only.

BUG=chromium:1007152
TEST=CQ passes

Change-Id: I492b45cc1e7e39d124169d89a6e2c1c81e4547a5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/2549441
Reviewed-by: Alex Klein <saklein@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>