fix: phpstan issue

Author: SMillerDev

src/PHPDraft/Out/OpenAPI/OpenApiRenderer.php

@@ -164,7 +164,8 @@ private function toOperation(HTTPRequest $request, Transition $transition, array
 
         foreach ($request->headers as $name => $value) {
             if ($name === 'Content-Type') { continue; }
-            if ($name === $this->base_data['API_KEY_HEADER'] ?? NULL) {
+            if (isset($this->base_data['API_KEY_HEADER']) 
+                && $this->base_data['API_KEY_HEADER'] === $name) {
                 $operation['security'] = [["api_key" => []]];
                 continue;
             }