[submodule] Update submodule sonic-utilities to the latest HEAD automatically (#21948)

#### Why I did it
src/sonic-utilities
```
* 51a2e9e - (HEAD -> master, origin/master, origin/HEAD) enable pfcwd for backplane ports (#3792) (17 hours ago) [Dashuai Zhang]
* 4bed4d7 - revert YANG check in db_migrator (#3793) (2 days ago) [jingwenxie]
* d6e1bf4 - Enhance list-checkpoints CLI (#3746) (2 days ago) [Xincun Li]
```
#### How I did it
#### How to verify it
#### Description for the changelog

Author: mssonicbld