update language code for kokoro phonemizer

[katstankiewicz]

Main kokoro pipeline takes in "en-us" as a valid language code, but the phonemizer only accepts aliases like a for en-us

[raghavm243512]

the aliasing is done on the deployment side right? what phenomizer are you referring to

[katstankiewicz]

the aliasing is done on the deployment side right? what phenomizer are you referring to

the aliasing is working properly for the main pipeline, but later on we see this error:

| File "/app/api/src/services/text_processing/phonemizer.py", line 82, in create_phonemizer
| raise ValueError(f"Unsupported language code: {language}")
| ValueError: Unsupported language code: en-us

I don't know where app/api/src/services/text_processing/phonemizer.py is, but as is, it only accepts the single letter language code

[raghavm243512]

not sure why this would have changed since we are using the same container, but this is for some odd reason what kokoro does