[submodule] Update submodule sonic-gnmi to the latest HEAD automatically (#16799)

#### Why I did it
src/sonic-gnmi
```
* df4d49f - (HEAD -> 202305, origin/202305) Install necessary debs instead of entire artifact in azp (#137) (12 hours ago) [Zain Budhwani]
```
#### How I did it
#### How to verify it
#### Description for the changelog
This commit is contained in:
mssonicbld 2023-10-08 16:32:21 +08:00 committed by GitHub
parent ddd932eb92
commit d675af7027
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23

@ -1 +1 @@
Subproject commit d1467d3bcf0f3dc5be17ded5d3cc11665ee527e5
Subproject commit df4d49fa16bde99f639b67d0db36574bc64dedae