[BUG] Alarm delay

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

停掉api，大约20分钟后发出报警

### Expected Behavior

停掉api，3分钟后发出报警

### Steps To Reproduce

1、启动一个测试服务，http api 返回 200
2、配置hertzbeat，http api监控，填写相关信息，检测正常，设置监控周期60秒
3、确认阈值规则，http api 可用性，触发次数3次
4、所有告警收敛、告警静默规则全部删除
5、运行一个小时，待系统稳定后，停掉测试api服务
6、大于15至20分钟后，报警发出

### Environment

```markdown
HertzBeat version(s):1.4.3 和 1.5.0 都有
```

### Debug logs

无

### Anything else?

无

Reproduce the delay with the HTTP API monitor using a 60-second interval and an availability threshold of three triggers, as described in the issue, on HertzBeat 1.4.3 or 1.5.0. Trace the alerting path and timing after stopping the test API; done means an alert is emitted about three minutes after three failed checks, without convergence or silence rules enabled.

Written by the indexing model from the issue text.