ci: update litellm requirement

Updates the requirements on [litellm](https://github.com/BerriAI/litellm) to permit the latest version.
- [Release notes](https://github.com/BerriAI/litellm/releases)
- [Commits](BerriAI/litellm@litellm_1.81.13-dev...v1.85.0)

---
updated-dependencies:
- dependency-name: litellm
  dependency-version: 1.85.0
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

pyproject.toml

@@ -46,7 +46,7 @@ dependencies = [
 [project.optional-dependencies]
 anthropic = ["anthropic>=0.21.0,<1.0.0"]
 gemini = ["google-genai>=1.32.0,<2.0.0"]
-litellm = ["litellm>=1.75.9,<=1.83.13", "openai>=1.68.0,<3.0.0"]
+litellm = ["litellm>=1.75.9,<=1.85.0", "openai>=1.68.0,<3.0.0"]
 llamaapi = ["llama-api-client>=0.1.0,<1.0.0"]
 mistral = ["mistralai>=1.8.2,<2.0.0"]
 ollama = ["ollama>=0.4.8,<1.0.0"]