Refactor TemplateEngine::getSharedTemplateGroupID() to use array_find() and add error handling

Author: Cyperghost

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

@@ -1044,16 +1044,17 @@ protected function getCompileFilePrefix(string $templateName): string
 
     private function getSharedTemplateGroupID(): int
     {
-        if (!isset($this->sharedTemplateGroupID)) {
-            /** @var TemplateGroup $templateGroup */
-            foreach (TemplateGroupCacheBuilder::getInstance()->getData() as $templateGroup) {
-                if ($templateGroup->templateGroupFolderName === '_wcf_shared/') {
-                    $this->sharedTemplateGroupID = $templateGroup->templateGroupID;
-                    break;
-                }
-            }
+        $templateGroup = \array_find(
+            TemplateGroupCacheBuilder::getInstance()->getData(),
+            static fn (TemplateGroup $group) => $group->templateGroupFolderName === '_wcf_shared/'
+        );
+
+        if ($templateGroup === null) {
+            throw new \RuntimeException('Shared template group not found');
         }
 
+        $this->sharedTemplateGroupID = $templateGroup->templateGroupID;
+
         return $this->sharedTemplateGroupID;
     }
 }