fix(student page): restore the 30min auth token update timer

恢复学生页面的认证令牌每30分钟自动更新的定时器逻辑，修复令牌超时失效的问题

src/views/Student/index.vue

@@ -4116,7 +4116,7 @@ const updateAuthToken = async () => {
     // if (authTokenUpdateTimer.value) {
     //   clearTimeout(authTokenUpdateTimer.value)
     // }
-    // authTokenUpdateTimer.value = setTimeout(updateAuthToken, 30 * 60 * 1000) as unknown as NodeJS.Timeout
+    authTokenUpdateTimer.value = setTimeout(updateAuthToken, 30 * 60 * 1000) as unknown as NodeJS.Timeout
     // authTokenUpdateTimer.value = setTimeout(updateAuthToken, 10 * 1000) as unknown as NodeJS.Timeout
   }
   catch (error) {