Fix resource leaks in runtime and server components

[rbren]

This PR fixes file descriptor and network connection leaks identified in the OpenHands project. The changes include:

Changes

1. Request Sessions:

   • Added proper cleanup of request sessions in all runtime implementations
   • Added error handling and logging for session cleanup failures
   • Added checks to prevent NullPointerExceptions during cleanup
   • Ensured sessions are closed even if runtime stop fails

2. WebSocket Connections:

   • Added proper cleanup of WebSocket connections in the server
   • Added async-safe WebSocket closure using the event loop
   • Added error handling and logging for WebSocket cleanup failures
   • Nulled out WebSocket references after cleanup

3. Runtime Resources:

   • Added proper cleanup sequence for runtime resources
   • Added error handling for each cleanup step
   • Added nulling of references after cleanup to help garbage collection
   • Added logging for cleanup failures

4. Google Cloud Storage:

   • Added proper cleanup of Google Cloud storage clients
   • Added finalizer to ensure cleanup on object destruction
   • Added state tracking to prevent double-close issues
   • Added error handling and logging for cleanup failures

Files Changed

• openhands/runtime/impl/remote/remote_runtime.py
• openhands/server/session/session.py
• openhands/server/session/agent_session.py
• openhands/storage/google_cloud.py

These changes should help prevent file descriptor and network connection leaks by ensuring proper cleanup of resources in all cases, including error scenarios.

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To run this PR locally, use the following command:

docker run -it --rm   -p 3000:3000   -v /var/run/docker.sock:/var/run/docker.sock   --add-host host.docker.internal:host-gateway   -e SANDBOX_RUNTIME_CONTAINER_IMAGE=docker.all-hands.dev/all-hands-ai/runtime:8c1fa93-nikolaik   --name openhands-app-8c1fa93   docker.all-hands.dev/all-hands-ai/openhands:8c1fa93