Move the OWNERS file for goma.star to its new location.

Change-Id: I269cf8994e966eb9dae19e7c6c7c86e66e2f8a89
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1918085
Auto-Submit: Garrett Beaty <gbeaty@chromium.org>
Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#715475}

infra/config/buckets/OWNERS

+per-file goma.star=file:../GOMA_OWNERS

infra/config/buckets/ci/OWNERS

-per-file goma.star=file:../../GOMA_OWNERS