[submodule] Update submodule dhcprelay to the latest HEAD automatical…

…ly (sonic-net#17140)

#### Why I did it
src/dhcprelay
```
* 40c6877 - (HEAD -> master, origin/master, origin/HEAD) [CodeQL] fix unmet dependency for `build-swss-common` (#44) (30 hours ago) [Jing Zhang]
```
#### How I did it
#### How to verify it
#### Description for the changelog