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- Fixed outdated URLs in docs and comments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/components/setting/mods/misc-viewer.tsx

@@ -216,7 +216,7 @@ export const MiscViewer = forwardRef<DialogRef>((props, ref) => {
             spellCheck="false"
             sx={{ width: 250, marginLeft: "auto" }}
             value={values.defaultLatencyTest}
-            placeholder="https://www.gstatic.com/generate_204"
+            placeholder="https://cp.cloudflare.com/generate_204"
             onChange={(e) =>
               setValues((v) => ({ ...v, defaultLatencyTest: e.target.value }))
             }