[submodule] Update submodule dhcpmon to the latest HEAD automatically (#23834)

#### Why I did it
src/dhcpmon
```
* f08f25e - (HEAD -> master, origin/master, origin/HEAD) Optimize clear counter logic (#49) (3 days ago) [Yaqiang Zhu]
```
#### How I did it
#### How to verify it
#### Description for the changelog

Author: mssonicbld