update babel.config.js

ui.frontend/babel.config.js

@@ -20,13 +20,16 @@ module.exports = (api, opts = {}) => {
  // module the default value will cause the imports from the umd
  // libraries (@adobe/) to be not recognized anymore
  sourceType: 'unambiguous'
- }
+ };
 
  // Remove react-refresh/babel as this causes issues with the modules
  // extracted using the mini-css-extract-plugin. sources suggest to exclude
  // node_modules from babel which we cannot do because of peregrine.
  // We should fix this in peregrine (make it configureable)
- config.plugins = config.plugins.filter(plugin => plugin !== 'react-refresh/babel');
+ config.plugins = [
+ ...config.plugins.filter(plugin => plugin !== 'react-refresh/babel'),
+ '"@babel/plugin-transform-optional-chaining"'
+ ];
 
  return config;
-}
+};