Add tenacity as a dependency to support LM retries with LiteLLM

[dbczumar]

Add tenacity as a dependency to support LiteLLM retries

[dbczumar]

LiteLLM uses tenacity==8.2.3 for testing: https://github.com/BerriAI/litellm/blob/b73039b28337c04ac87eea8e0be11186f142f38f/requirements.txt#L46.

I've confirmed that 8.2.3 and 9.0.0 appear to work just fine via the following script using an Azure OpenAI + Databricks endpoint with an aggressive rate limit of 1QPM:

import litellm
import uuid


litellm.set_verbose=True
for i in range(100):
    print(litellm.completion(
        model="databricks/coreyazureopenai",
        messages=[{"role": "user", "content": "You are a helpful assistant." + uuid.uuid4().hex}],
        retry_strategy="exponential_backoff_retry",
        num_retries=10,
    ))

Accordingly, >=8.2.3 appears appropriate

[dbczumar]

This is the only material change. Everything else is just linter formatting