Explicitly enable @babel/plugin-proposal-optional-chaining to fix build failures (#24504)

babel.config.js

@@ -20,6 +20,7 @@ module.exports = (api) => {
     plugins: [
       ['react-intl', { messagesDir: './build/messages' }],
       'preval',
+      '@babel/plugin-proposal-optional-chaining',
       '@babel/plugin-proposal-nullish-coalescing-operator',
     ],
     overrides: [