refactor: Get rid of PHPStan issue.

phpstan.neon

@@ -1,7 +1,2 @@
 parameters:
     ignoreErrors:
-        -
-            message: "#Casting to array<int, string> something that\\'s already array<int, string>.#"
-            paths:
-                - src/CountryHandler/CountryHandler.php
-                - src/CountryHandler/Germany.php

src/CountryHandler/Austria.php

@@ -41,7 +41,7 @@ protected function hasValidRule(string $tin): bool
         $c8 = $this->digitAt($tin, 7);
         $c9 = $this->digitAt($tin, 8);
 
-        $sum = (int) array_sum([
+        $sum = array_sum([
             $c1,
             $c3,
             $c5,

src/CountryHandler/CountryHandler.php

@@ -91,7 +91,7 @@ protected function digitAt(string $str, int $index): int
     protected function digitsSum(int $int): int
     {
         return array_reduce(
-            (array) str_split((string) $int),
+            str_split((string) $int),
             static function (int $carry, string $digit): int {
                 return $carry + (int) $digit;
             },
@@ -106,14 +106,12 @@ static function (int $carry, string $digit): int {
      */
     protected function getAlphabeticalPosition(string $character): int
     {
-        return false !== ($return = array_combine(range('a', 'z'), range(1, 26))) ?
-            $return[strtolower($character)] :
-            0;
+        return 1 + array_flip(range('a', 'z'))[strtolower($character)];
     }
 
     protected function getLastDigit(int $number): int
     {
-        $split = (array) str_split((string) $number);
+        $split = str_split((string) $number);
 
         return (int) end($split);
     }

src/CountryHandler/Germany.php

@@ -59,7 +59,7 @@ protected function hasValidRule(string $tin): bool
 
     private function calculateCheckDigit(string $tin): int
     {
-        $chars = (array) str_split($tin);
+        $chars = str_split($tin);
         $remainder_mod_eleven = 10;
 
         for ($length = strlen($tin), $counter = 0; $length - 1 > $counter; ++$counter) {