MAPG-199 fix issues found by PHPStan

src/Response/JsonContent.php

@@ -9,6 +9,7 @@ class JsonContent extends ContentBase
 
     public function render(): void
     {
+        // @phpstan-ignore-next-line - SCRIPT_STARTED is defined in main.php
         $this->data['__debug__runtime'] = round((hrtime(true) - SCRIPT_STARTED) / 1e+6, 1);
 
         echo json_encode($this->data);