No space after fn for short arrow functions

.php-cs-fixer.dist.php

@@ -8,6 +8,7 @@
     ->setRules([
         '@Symfony' => true,
         'method_argument_space' => ['on_multiline' => 'ensure_fully_multiline'],
+        'function_declaration' => ['closure_fn_spacing' => 'none'],
         'single_line_empty_body' => true,
         'yoda_style' => [
             'equal' => false,