GHSA-g5ff-637f-6q2m: LiteLLM: internal_user_viewer arbitrary local file read via `vertex_ai_credentials`

An authenticated LiteLLM proxy user could read arbitrary local files from the proxy runtime by sending a crafted vertex_ai_credentials value to /utils/transform_request. The request-body safety blocklist rejected vertex_credentials but missed its alias vertex_ai_credentials, which let the value reach the Vertex AI credential loader and trigger a file read that is sent to an attacker-controlled URL.