[submodule] Update submodule linkmgrd to the latest HEAD automatically (

sonic-net#17721)

#### Why I did it
src/linkmgrd
```
* 2089ab6 - (HEAD -> 202305, origin/202305) Exclude DbInterface in PR coverage check (sonic-net#224) (3 hours ago) [Jing Zhang]
```
#### How I did it
#### How to verify it
#### Description for the changelog