chore(deps): bump litellm from 1.43.15 to 1.43.18 (All-Hands-AI#3466)

Bumps [litellm](https://github.com/BerriAI/litellm) from 1.43.15 to 1.43.18.
- [Release notes](https://github.com/BerriAI/litellm/releases)
- [Commits](BerriAI/litellm@v1.43.15...v1.43.18)

---
updated-dependencies:
- dependency-name: litellm
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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