[Python SDK] Using deprecated shutdown and startup events

[pocesar]

Describe the bug

FastAPI warns during the startup that the AgentServer class is using deprecated startup and shutdown events, but should be using lifespan instead

https://fastapi.tiangolo.com/advanced/events/?h=life#lifespan

Steps to reproduce

1. Go to '...'
2. Run '...'
3. See error

Expected behavior

Screenshots / Logs

Environment

• Control plane version:
• SDK version (if applicable):
• Deployment environment (local, docker, kubernetes, etc.):

Additional context

[DebanKsahu]

Let me pick this issue