fix(deps): bump litellm to ~=1.83.0 to fix critical vulnerabilities

Addresses:
- GHSA-jjhc-v7c2-5hh6: OIDC authentication bypass via cache key collision (critical)
- GHSA-53mr-6c8q-9789: Privilege escalation via unrestricted proxy config (high)

Both vulnerabilities are fixed in litellm 1.83.0+.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: gkorland

pyproject.toml

@@ -7,7 +7,7 @@ requires-python = ">=3.12"
 dependencies = [
     "fastapi~=0.135.1",
     "uvicorn~=0.42.0",
-    "litellm~=1.82.0",
+    "litellm~=1.83.0",
     "falkordb~=1.6.0",
     "psycopg2-binary~=2.9.11",
     "pymysql~=1.1.0",