ci: update litellm requirement from <=1.83.13,>=1.75.9 to >=1.75.9,<=1.85.1

[dependabot]

Updates the requirements on litellm to permit the latest version.

Release notes

Sourced from litellm's releases.

v1.85.1

Verify Docker Image Signature

All LiteLLM Docker images are signed with cosign. Every release is signed with the same key introduced in commit 0112e53.

Verify using the pinned commit hash (recommended):

A commit hash is cryptographically immutable, so this is the strongest way to ensure you are using the original signing key:

cosign verify \
  --key https://raw.githubusercontent.com/BerriAI/litellm/0112e53046018d726492c814b3644b7d376029d0/cosign.pub \
  ghcr.io/berriai/litellm:v1.85.1

Verify using the release tag (convenience):

Tags are protected in this repository and resolve to the same key. This option is easier to read but relies on tag protection rules:

cosign verify \
  --key https://raw.githubusercontent.com/BerriAI/litellm/v1.85.1/cosign.pub \
  ghcr.io/berriai/litellm:v1.85.1

Expected output:

The following checks were performed on each of these signatures:
  - The cosign claims were validated
  - The signatures were verified against the specified public key

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Full Changelog: BerriAI/litellm@v1.85.0...v1.85.1

Commits

• f9c2a41 chore: update uv.lock for 1.85.1
• f506a32 bump: version 1.85.0 → 1.85.1
• 75c72c5 fix(vertex_ai): omit function_call id on Vertex Gemini 3.5+ tool turns (#28324)
• c621f58 fix(spend_counter): seed Redis counter via SET NX to prevent cross-pod double...
• cbf9ffe Day 0 support : Gemini 3.5 Flash (#28268)
• e58a561 Merge pull request #27906 from BerriAI/litellm_internal_staging
• de1747d fix(spend-logs): redact echoed prompts in error_information (LIT-2992) (#27689)
• 117b036 Merge pull request #27907 from BerriAI/yj_build_2_may13
• a2bb7aa Merge pull request #27908 from BerriAI/yj_bump_may13
• e838a40 uv lock
• Additional commits viewable in compare view

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