Fix licence

Author: edznux-dd

libdd-trace-normalization/fuzz/fuzz_targets/fuzz_normalize_span.rs

@@ -1,3 +1,6 @@
+// Copyright 2023-Present Datadog, Inc. https://www.datadoghq.com/
+// SPDX-License-Identifier: Apache-2.0
+
 #![no_main]
 
 use libdd_trace_normalization::fuzz::{fuzz_normalize_span, FuzzSpan};