fix for psalm

Author: Dmytro Vyshnevskyi

src/Core/src/Signer/SignerV4.php

@@ -321,7 +321,9 @@ private function buildCanonicalQuery(Request $request): string
             return '';
         }
 
-        uksort($query, static fn ($a, $b) => strcmp(rawurlencode($a), rawurlencode($b)));
+        uksort($query, static function (string $a, string $b): int {
+            return strcmp(rawurlencode($a), rawurlencode($b));
+        });
         $encodedQuery = [];
         foreach ($query as $key => $values) {
             if (!\is_array($values)) {