devserver: Remove unused APIs

remove for_update use case as devserver is not being used to generate
update payloads anymore.

Remove the xbuddy_list API as there is no use case for this either.

BUG=chromium:1008058
TEST=./devserver_integration_test.py

Change-Id: Idb8fb6d5c42bb1555611d241fb031d21fb4707b1
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/2485248
Tested-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Jae Hoon Kim <kimjae@chromium.org>
Commit-Queue: Amin Hassani <ahassani@chromium.org>
2 files changed