bugfix/current-deprecated Return type of ClickHouseDB\Statement::current() should either be compatible with Iterator::current()

Author: m1khal3v

src/Statement.php

@@ -581,6 +581,7 @@ public function rewind(): void {
     /**
      * @return mixed
      */
+    #[\ReturnTypeWillChange]
     public function current() {
         if (!isset($this->array_data[$this->iterator])) {
             return null;