Fix Groq invalid self.config reference

[aidando73]

What does this PR do?

Contributes towards: #432

RE: #609

I missed this one while refactoring. Fixes:

Traceback (most recent call last):
  File "/Users/aidand/dev/llama-stack/llama_stack/distribution/server/server.py", line 191, in endpoint
    return await maybe_await(value)
  File "/Users/aidand/dev/llama-stack/llama_stack/distribution/server/server.py", line 155, in maybe_await
    return await value
  File "/Users/aidand/dev/llama-stack/llama_stack/providers/utils/telemetry/trace_protocol.py", line 101, in async_wrapper
    result = await method(self, *args, **kwargs)
  File "/Users/aidand/dev/llama-stack/llama_stack/distribution/routers/routers.py", line 156, in chat_completion
    return await provider.chat_completion(**params)
  File "/Users/aidand/dev/llama-stack/llama_stack/providers/utils/telemetry/trace_protocol.py", line 101, in async_wrapper
    result = await method(self, *args, **kwargs)
  File "/Users/aidand/dev/llama-stack/llama_stack/providers/remote/inference/groq/groq.py", line 127, in chat_completion
    response = self._get_client().chat.completions.create(**request)
  File "/Users/aidand/dev/llama-stack/llama_stack/providers/remote/inference/groq/groq.py", line 143, in _get_client
    return Groq(api_key=self.config.api_key)
AttributeError: 'GroqInferenceAdapter' object has no attribute 'config'. Did you mean: '_config'?

Test Plan

Environment:

export GROQ_API_KEY=<api-key>

# build.yaml and run.yaml files
wget https://raw.githubusercontent.com/aidando73/llama-stack/9165502582cd7cb178bc1dcf89955b45768ab6c1/build.yaml
wget https://raw.githubusercontent.com/aidando73/llama-stack/9165502582cd7cb178bc1dcf89955b45768ab6c1/run.yaml

# Create environment if not already
conda create --prefix ./envs python=3.10
conda activate ./envs

# Build
pip install -e . && llama stack build --config ./build.yaml --image-type conda

# Activate built environment
conda activate llamastack-groq

Manual

llama stack run ./run.yaml --port 5001

Via this Jupyter notebook: https://github.com/aidando73/llama-stack/blob/9165502582cd7cb178bc1dcf89955b45768ab6c1/hello.ipynb

Sources

Please link relevant resources if necessary.

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Ran pre-commit to handle lint / formatting issues.
• Read the contributor guideline,
  Pull Request section?
• Updated relevant documentation.
• Wrote necessary unit or integration tests.