feat: integrate with flysystem for xml data

src/BusProNet/XmlLoader/PickupLoader.php

@@ -16,7 +16,7 @@ class PickupLoader extends AbstractLoader
             return $this->cache->get('bpn_pickups', function (ItemInterface $item) use ($filename) {
                 $item->expiresAfter(3 * 60 * 60);
 
-                $crawler = new Crawler(file_get_contents($this->xmlPath . '/' . $filename));
+                $crawler = $this->loadXml($filename);
                 $pickupNodes = $crawler->filterXPath('//zustiege/zustieg');
 
                 $pickups = [];
@@ -40,6 +40,13 @@ class PickupLoader extends AbstractLoader
         return $pickups[$id] ?? null;
     }
 
+    private function loadXml(?string $filename = 'zustiege.xml'): Crawler
+    {
+        $xml = $this->xmlExport->read($filename);
+
+        return new Crawler($xml);
+    }
+
     public function parseXml(Crawler $node): Pickup
     {
         $pickup = new Pickup();