fix(DomainSwitcher): 为fetch请求添加HEAD方法

避免不必要的响应体传输，提升请求效率

src/components/widget/DomainSwitcher.astro

@@ -113,6 +113,7 @@ const officialSites = siteConfig.officialSites || [];
                 const timeoutId = setTimeout(() => controller.abort(), 5000);
                 
                 await fetch(url, { 
+                    method: 'HEAD',
                     mode: 'no-cors', 
                     cache: 'no-store',
                     signal: controller.signal
@@ -169,3 +170,4 @@ const officialSites = siteConfig.officialSites || [];
     });
 </script>
 
+