Update release-notes/opensearch-release-notes-2.19.0.md

Co-authored-by: Sayali Gaikawad <61760125+gaiksaya@users.noreply.github.com>
Signed-off-by: Rishabh Singh <rishabhksingh@gmail.com>

release-notes/opensearch-release-notes-2.19.0.md

@@ -1153,7 +1153,7 @@ fix(deps): update dependency org.scala-lang:scala-library to v2.13.9 ([#496](htt
 ### Opensearch Security Analytics
 
 
-* optimize sigma aggregation rule based detectors execution workflow ([#1418](https://github.com/opensearch-project/security-analytics/pull/1418))
+* Optimize sigma aggregation rule based detectors execution workflow ([#1418](https://github.com/opensearch-project/security-analytics/pull/1418))
 * Adding various OCSF 1.1 fields to log type static mappings ([#1403](https://github.com/opensearch-project/security-analytics/pull/1403))