Release: update changelog for 11.4.0 (grafana#97499)

* Update changelog

* Update CHANGELOG.md

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Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Jev Forsberg <46619047+baldm0mma@users.noreply.github.com>

Author: 3 people

CHANGELOG.md

@@ -1,3 +1,12 @@
+<!-- 11.4.0 START -->
+
+# 11.4.0 (2024-12-05)
+
+### Features and enhancements
+
+- **Cloudwatch:** OpenSearch PPL and SQL support in Logs Insights
+
+<!-- 11.4.0 END -->
 <!-- 11.3.2 START -->
 
 # 11.3.2 (2024-12-04)