[COMPLIANCE] Add Copyright and License Headers (#580)

hashicorp-copywrite[bot] · web-flow · commit 1462fd5e80ad · 2023-11-20T11:25:35.000-07:00
Co-authored-by: hashicorp-copywrite[bot] &lt;110428419+hashicorp-copywrite[bot]@users.noreply.github.com&gt;
diff --git a/bench_test.go b/bench_test.go
@@ -1,3 +1,6 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
 package raft
 
 import (
