add gCube 5.15.4

open/gcube-5.15.4.yaml

@@ -0,0 +1,16 @@
+#Release gCube 5.15.4 
+        
+gCube_release:
+  Version: 5.15.4
+  Components:
+     
+     Libraries:
+       - name: geoportal-data-common
+         version: 2.2.0
+       - name: google-analytics4-hook
+         version: 1.0.0
+         
+     Portlets:
+       - name: geoportal-data-viewer-app
+         version: 3.5.0
+