add boto3 to deps

Author: kelsey-wong

services/chat-backend/pyproject.toml

@@ -6,6 +6,7 @@ readme = "README.md"
 requires-python = ">=3.10"
 dependencies = [
     "azure-identity>=1.19.0",
+    "boto3>=1.34.0",
     "fastapi>=0.115.5",
     "gunicorn>=23.0.0",
     "pydantic-settings>=2.6.1",