refactor(消息通知): 修改轮询通知数的时间范围

--bug=1016454 --user=刘瑞斌 [消息通知]github#17554浏览器页面最小化挂一晚上后，第二天打开直接死机 https://www.tapd.cn/55049933/s/1235760

Closes #17554

backend/src/main/java/io/metersphere/base/mapper/ext/ExtNotificationMapper.xml

@@ -40,7 +40,7 @@
 
     <select id="countNotification" resultType="java.lang.Integer">
         select count(*) from notification
-        where receiver = #{notification.receiver}
+        where receiver = #{notification.receiver} AND create_time &gt; (UNIX_TIMESTAMP() - 3600) * 1000
         <if test="notification.type != null">
             and type = #{notification.type}
         </if>