chore(runtime): Add logging for /server_info endpoint

[xingyaoww]

Added INFO level logging when the /server_info endpoint is called to improve observability of server status requests.

This allow us to better debug cases where runtime dies - so we can know better if it is caused by OOM or something else.

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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:f8c994d-nikolaik   --name openhands-app-f8c994d   docker.all-hands.dev/all-hands-ai/openhands:f8c994d