Update OSD repo to 2.3 (opensearch-project#2586)

Signed-off-by: Louis Chu <lingzhichu.clz@gmail.com>

Signed-off-by: Louis Chu <lingzhichu.clz@gmail.com>

Author: noCharger

manifests/2.3.0/opensearch-dashboards-2.3.0.yml

@@ -9,7 +9,7 @@ ci:
 components:
   - name: OpenSearch-Dashboards
     repository: https://github.com/opensearch-project/OpenSearch-Dashboards.git
-    ref: 2.x
+    ref: '2.3'
   - name: functionalTestDashboards
     repository: https://github.com/opensearch-project/opensearch-dashboards-functional-test.git
     ref: '2.3'