fix(deps): bump litellm to >=1.83.7 to patch GHSA-xqmj-j6mv-4862

[amrit110]

Summary

• Bumps litellm lower bound from >=1.83.0 to >=1.83.7 to address GHSA-xqmj-j6mv-4862 — a remote code execution vulnerability in LiteLLM's proxy server POST /prompts/test endpoint (fixed in 1.83.7)
• Relaxes pydantic bound from >=2.13.0 to >=2.12.5 to remain compatible with litellm 1.83.7+'s pydantic~=2.12.5 requirement; safe because infermesh only uses BaseModel
• Ignores CVE-2026-3219 in CI audit — affects pip itself, no fix version available
• Bumps version to 0.3.1

Test plan

• uv lock resolves cleanly with litellm >=1.83.7
• Existing tests pass

[fcogidi]

Thanks for this!
Looks like pip is upgradable with uv sync --upgrade-package pip, so I upgraded it, as well as the pip-audit command in the ci.