fix: unify default latency test URL and update workflows/backend logic

- All delay test logic, Rust MihomoManager, API, cmds, delay.ts, settings, and group editor now use the Cloudflare 204 test URL
- Fixed outdated URLs in docs and comments
- Fix Github Actions workflow: unexpected neeeds run

src/services/cmds.ts

@@ -183,7 +183,7 @@ export async function cmdGetProxyDelay(
   url?: string,
 ) {
   // 确保URL不为空
-  const testUrl = url || "https://www.gstatic.com/generate_204";
+  const testUrl = url || "https://cp.cloudflare.com/generate_204";
   console.log(
     `[API] 调用延迟测试API，代理: ${name}, 超时: ${timeout}ms, URL: ${testUrl}`,
   );