[submodule] Update submodule sonic-utilities to the latest HEAD automatically (#21448)

#### Why I did it
src/sonic-utilities
```
* a8f55a34 - (HEAD -> 202411, origin/202411) [Arista] Add 7060X6-64 to GCU Validator (#3719) (22 hours ago) [mssonicbld]
```
#### How I did it
#### How to verify it
#### Description for the changelog

Author: mssonicbld