Modify LiteLLM dependency constraints for compromised packages

[nsphung]

Updated litellm dependency to exclude specific versions due to security issues.

Why are these changes needed?

Pinned upper bound for litellm[proxy] to avoid compromised versions 1.82.7 / 1.82.8

Related issue number

Details on BerriAI/litellm#24518

Replicated like on langchain-ai/langchain-litellm#103

Checks

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• I've added tests (if relevant) corresponding to the changes introduced in this PR.
• I've made sure all auto checks have passed.

[CLAassistant]

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[marklysze]

@nsphung thank you for highlighting this and suggesting the change. As the litellm version in the interop-crewai extra is already restricted to 1.76.3 or below, the affected LiteLLM packages won't be retrieved.

It is very useful to have this PR as evidence of this issue but at this stage we won't merge into main.

Thank you!