Remove net-libs/grpc

The dependencies on the packages have
been removed. This CL removes the package
ebuild.

BUG=b/340935901
TEST=presubmit and validation tests
RELEASE_NOTE=Removed net-libs/grpc.

Change-Id: Ia99f741287a46d14df14ea6cb8751f1330a4836c
Reviewed-on: https://cos-review.googlesource.com/c/third_party/overlays/chromiumos-overlay/+/73594
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Robert Kolchmeyer <rkolchmeyer@google.com>
20 files changed