[AUTO] Add release notes for 2.19.6 (#1425)

Add release notes for 2.19.6

Signed-off-by: opensearch-ci-bot <opensearch-infra@amazon.com>

Author: opensearch-ci-bot

release-notes/opensearch-flow-framework.release-notes-2.19.6.0.md

@@ -0,0 +1,7 @@
+## Version 2.19.6 Release Notes
+
+Compatible with OpenSearch and OpenSearch Dashboards version 2.19.6
+
+### Infrastructure
+
+* Add CI mirror to avoid Maven Central throttling during builds ([#1429](https://github.com/opensearch-project/flow-framework/pull/1429))