[COMPLIANCE] Add Copyright and License Headers

hashicorp-copywrite[bot] · web-flow · commit 1be81099f547 · 2023-12-25T16:12:56.000Z
diff --git a/internal/provider/provider_custom_diffs_test.go b/internal/provider/provider_custom_diffs_test.go
@@ -1,3 +1,6 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
 package provider
 
 import (
