[submodule] Update submodule sonic-utilities to the latest HEAD autom…

…atically (#18673)

#### Why I did it
src/sonic-utilities
```
* 21f69fb5 - (HEAD -> 202311, origin/202311) [graceful reboot] Add watchdog, add execution of pre_reboot_hook, fix --force flag bug (#3204) (11 hours ago) [Vadym Hlushko]
```
#### How I did it
#### How to verify it
#### Description for the changelog