no_superfluous_phpdoc_tags: allow mixed as its needed for precise types for PHPStan

Author: Slamdunk

lib/Config.php

@@ -104,7 +104,7 @@ public function __construct(string $type = self::APP_V2, array $overriddenRules
             'no_php4_constructor'                               => true,
             'no_short_echo_tag'                                 => true,
             'no_superfluous_elseif'                             => true,
-            'no_superfluous_phpdoc_tags'                        => true,
+            'no_superfluous_phpdoc_tags'                        => ['allow_mixed' => true],
             'no_unneeded_control_parentheses'                   => true,
             'no_unreachable_default_argument_value'             => true,
             'no_unset_cast'                                     => true,