Get the templateGroupID for the shared templates from the cache

wcfsetup/install/files/lib/system/template/TemplateEngine.class.php

@@ -4,14 +4,14 @@
 
 use Laminas\Diactoros\Stream;
 use Psr\Http\Message\StreamInterface;
+use wcf\data\template\group\TemplateGroup;
 use wcf\data\template\Template;
 use wcf\system\cache\builder\TemplateGroupCacheBuilder;
 use wcf\system\cache\builder\TemplateListenerCodeCacheBuilder;
 use wcf\system\event\EventHandler;
 use wcf\system\exception\SystemException;
 use wcf\system\Regex;
 use wcf\system\SingletonFactory;
-use wcf\system\WCF;
 use wcf\util\DirectoryUtil;
 use wcf\util\HeaderUtil;
 use wcf\util\StringUtil;
@@ -1045,14 +1045,18 @@ protected function getCompileFilePrefix(string $templateName): string
     private function getSharedTemplateGroupID(): int
     {
         if (!isset($this->sharedTemplateGroupID)) {
-            $sql = "SELECT  templateGroupID
-                    FROM    wcf1_template_group
-                    WHERE   templateGroupFolderName = ?";
-            $statement = WCF::getDB()->prepare($sql);
-            $statement->execute(['_wcf_shared/']);
+            $templateGroup = \array_find(
+                $this->templateGroupCache,
+                static fn(TemplateGroup $group) => $group->templateGroupFolderName === '_wcf_shared/'
+            );
 
-            $this->sharedTemplateGroupID = $statement->fetchSingleColumn();
+            if ($templateGroup === null) {
+                throw new \RuntimeException('Shared template group not found');
+            }
+
+            $this->sharedTemplateGroupID = $templateGroup->templateGroupID;
         }
+
         return $this->sharedTemplateGroupID;
     }
 }