Bump version to 2.19.4 (#10551)

Author: gaiksaya

package.json

@@ -11,7 +11,7 @@
     "dashboarding"
   ],
   "private": true,
-  "version": "2.19.3",
+  "version": "2.19.4",
   "branch": "2.x",
   "types": "./opensearch_dashboards.d.ts",
   "tsdocMetadata": "./build/tsdoc-metadata.json",
@@ -516,4 +516,4 @@
     "node": ">=14.20.1 <19",
     "yarn": "^1.22.10"
   }
-}
+}