Increate PHPStan level to 5

Signed-off-by: Henrique Moody <henriquemoody@gmail.com>

library/Rules/In.php

@@ -40,7 +40,7 @@ final class In extends AbstractRule
     /**
      * Initializes the rule with the haystack and optionally compareIdentical flag.
      *
-     * @param array|string $haystack
+     * @param mixed $haystack
      * @param bool $compareIdentical
      */
     public function __construct($haystack, bool $compareIdentical = false)

phpstan.neon.dist

@@ -7,7 +7,8 @@ parameters:
     - phpt
   ignoreErrors:
     - '/Call to an undefined static method Respect\\Validation\\Validator::iDoNotExistSoIShouldThrowException/'
-  level: 3
+    - '/Parameter #2 $locale of function setlocale expects array|string|null, int given./'
+  level: 5
   paths:
     - library/
     - tests/