change fixer config

.php-cs-fixer.php

@@ -6,9 +6,7 @@ declare(strict_types=1);
  * @since 2.7.0
  */
 
-return (new PhpCsFixer\Config())
-    ->setRiskyAllowed(true)
-    ->setRules([
+$rules = [
     '@PSR12' => true,
     '@Symfony' => true,
     '@PhpCsFixer' => true,
@@ -68,8 +66,17 @@ return (new PhpCsFixer\Config())
     'php_unit_test_class_requires_covers' => false,
     'global_namespace_import' => false,
     'phpdoc_order' => false,
-        'no_useless_concat_operator' => false,
-    ])
+];
+
+if (PHP_VERSION_ID > 70400) {
+    $rules['no_useless_concat_operator'] = false;
+}
+
+// 'no_useless_concat_operator' => false,
+
+return (new PhpCsFixer\Config())
+    ->setRiskyAllowed(true)
+    ->setRules($rules)
     ->setFinder(
         PhpCsFixer\Finder::create()
             ->in(__DIR__ . '/src')