Add missing license header 2

Signed-off-by: Lukasz Gryglicki <lgryglicki@cncf.io>

Assisted by [OpenAI](https://platform.openai.com/)

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Author: lukaszgryglicki

utils/otel_dd/api_usage_stats_ddog.py

@@ -1,4 +1,8 @@
 #!/usr/bin/env python3
+
+# Copyright The Linux Foundation and each contributor to CommunityBridge.
+# SPDX-License-Identifier: MIT
+
 """
 Query Datadog span events and output per-route API usage statistics as CSV.