Check file existence instead of asset array

Fix the disk backlog during scoreboard pictures rendering.

Author: cubercsl

webapp/src/Service/DOMJudgeService.php

@@ -1386,9 +1386,8 @@ public function assetPath(?string $name, string $type, bool $fullPath = false, ?
         }
 
         if (isset($dir)) {
-            $assets = $this->getAssetFiles($dir);
             foreach (static::MIMETYPE_TO_EXTENSION as $extension) {
-                if ($forceExtension === $extension || (!$forceExtension && in_array($name . '.' . $extension, $assets))) {
+                if ($forceExtension === $extension || (!$forceExtension && file_exists($dir . '/' . $name . '.' . $extension))) {
                     return sprintf('%s%s/%s.%s', $prefix, $dir, $name, $extension);
                 }
             }