Make the model collaborative in JupyterLite

Author: davidbrochart

python/jupytergis_core/src/jgisplugin/modelfactory.ts

@@ -18,8 +18,7 @@ export class JupyterGISModelFactory
   /**
    * Whether the model is collaborative or not.
    */
-  readonly collaborative =
-    document.querySelectorAll('[data-jupyter-lite-root]')[0] === undefined;
+  readonly collaborative = true;
 
   /**
    * The name of the model.