Fix Prettier formatting in Pro dummy webpack config

The commonWebpackConfig.js file had a long conditional that needed to be
split across multiple lines according to Prettier rules in the Pro package.

This was not caught by pre-commit hooks because the root .prettierignore
excludes react_on_rails_pro/, but CI runs linting separately in that
directory with its own rules.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: justin808

react_on_rails_pro/spec/dummy/config/webpack/commonWebpackConfig.js

@@ -29,7 +29,11 @@ const baseClientWebpackConfig = generateWebpackConfig();
 
 // Add sass-resources-loader to all SCSS rules (both .scss and .module.scss)
 baseClientWebpackConfig.module.rules.forEach((rule) => {
-  if (Array.isArray(rule.use) && rule.test && (rule.test.test('example.scss') || rule.test.test('example.module.scss'))) {
+  if (
+    Array.isArray(rule.use) &&
+    rule.test &&
+    (rule.test.test('example.scss') || rule.test.test('example.module.scss'))
+  ) {
     rule.use.push(sassLoaderConfig);
   }
 });