Add trailing_comma_in_multiline to .php-cs-fixer.dist.php (#4001)

Author: Kilbourne

.php-cs-fixer.dist.php

@@ -9,5 +9,6 @@
 return (new PhpCsFixer\Config())
     ->setRules([
         '@PER-CS' => true,
+        'trailing_comma_in_multiline' => ['elements' => ['arguments', 'array_destructuring', 'arrays']], // For PHP 7.4 compatibility
     ])
     ->setFinder($finder);