[submodule] Update submodule dhcprelay to the latest HEAD automatically (#16566)

#### Why I did it
src/dhcprelay
```
* 2b33d76 - (HEAD -> master, origin/master, origin/HEAD) dhcpv6 per interface counter support (#43) (7 days ago) [jcaiMR]
```
#### How I did it
#### How to verify it
#### Description for the changelog

Author: mssonicbld