feat: mask api key for cerebriumai llm (#14272)
- **Description:** Masking API key for CerebriumAI LLM to protect user
secrets.
- **Issue:** #12165
- **Dependencies:** None
- **Tag maintainer:** @eyurtsev
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Signed-off-by: Yuchen Liang <yuchenl3@andrew.cmu.edu>
Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>
