[submodule] Update submodule sonic-swss to the latest HEAD automatica…

…lly (sonic-net#21012)

#### Why I did it
src/sonic-swss
```
* 42e9feaa - (HEAD -> 202405, origin/202405) [buffer] indicate shared pool by putting a very small shared buffer pool size (sonic-net#3387) (61 minutes ago) [Junchao-Mellanox]
```
#### How I did it
#### How to verify it
#### Description for the changelog