Add protobuf dependency (>=7.35.0)

Add protobuf as a direct dependency in pyproject.toml to provide required protocol buffer support. Regenerate the project's lockfile to reflect the new dependency.

Author: edwinjosechittilappilly

pyproject.toml

@@ -45,6 +45,7 @@ dependencies = [
     "structlog>=25.4.0",
     "zxcvbn>=4.5.0",
     "prometheus-fastapi-instrumentator>=7.1.0",
+    "protobuf>=7.35.0",
     "litellm==1.83.14",
     "pyyaml>=6.0",
     "tiktoken>=0.7.0",