Utility: Fix issues reported by CI workflow

Author: lkrms

src/Toolkit/Utility/Str.php

@@ -511,6 +511,12 @@ public static function decodeBase32(string $string, bool $strict = false): strin
     {
         $string = self::upper(rtrim($string, '='));
 
+        // Handle different `str_split('')` behaviour between PHP 8.2+ and
+        // earlier versions
+        if ($string === '') {
+            return '';
+        }
+
         $bytes = '';
         $currentByte = 0;
         $currentBits = 0;

tests/unit/Toolkit/Utility/StrTest.php

@@ -886,6 +886,9 @@ public function testDecodeBase32(?string $expected, string $string, bool $strict
         $this->assertSame($expected, Str::decodeBase32($string, $strict));
     }
 
+    /**
+     * @return array<array{string|null,string,2?:bool}>
+     */
     public function decodeBase32provider(): array
     {
         return [