chore: fix phpstan errors

src/BusProNet/XmlParser/BookingInsurancesParser.php

@@ -15,6 +15,7 @@ use Symfony\Component\DomCrawler\Crawler;
  */
 class BookingInsurancesParser extends AbstractParser
 {
+    /** @return array<string, Insurance> */
     public function parse(Crawler $result): array
     {
         $insurances = [];