Disable pruning for automated sync of root apps

This ensures that we can move component instances between different root
apps without having to manually disable auto-sync for the root apps on
all clusters that use the component.

component/app.jsonnet

@@ -45,6 +45,13 @@ local root_app(team) =
         else
           'manifests/apps-%s/' % team,
       },
+      syncPolicy+: {
+        automated+: {
+          // don't prune resources managed by root app so we don't accidentally
+          // delete apps when moving them between root apps
+          prune: false,
+        },
+      },
     },
   };