m/n/c/network: implement ARP announcements

This implements ARP announcements in the Metropolis network stack.
Its intent is to help IP stacks on the same broadcast domain to update
their ARP entries once a Metropolis network stack comes up.
The format of the ARP packets is chosen to bypass most EVPN ARP
suppression mechanisms to ensure this also works with these systems.

Change-Id: I2db1248f7034ea56930cf6f4a93de598b0f8c7de
Reviewed-on: https://review.monogon.dev/c/monogon/+/3074
Reviewed-by: Leopold Schabel <leo@monogon.tech>
Tested-by: Jenkins CI
diff --git a/third_party/go/repositories.bzl b/third_party/go/repositories.bzl
index dcffde4..ca0dd2e 100644
--- a/third_party/go/repositories.bzl
+++ b/third_party/go/repositories.bzl
@@ -3562,6 +3562,18 @@
         version = "v6.2.2",
     )
     go_repository(
+        name = "com_github_mdlayher_arp",
+        importpath = "github.com/mdlayher/arp",
+        sum = "h1:ql8x//rJsHMjS+qqEag8n3i4azw1QneKh5PieH9UEbY=",
+        version = "v0.0.0-20220512170110-6706a2966875",
+    )
+    go_repository(
+        name = "com_github_mdlayher_ethernet",
+        importpath = "github.com/mdlayher/ethernet",
+        sum = "h1:2oDp6OOhLxQ9JBoUuysVz9UZ9uI6oLUbvAZu0x8o+vE=",
+        version = "v0.0.0-20220221185849-529eae5b6118",
+    )
+    go_repository(
         name = "com_github_mdlayher_ethtool",
         importpath = "github.com/mdlayher/ethtool",
         replace = "github.com/monogon-dev/ethtool",