fix: Disable deliberate exception in /ping endpoint in production environment

[plural-copilot]

Summary:

The /ping endpoint in the FastAPI app deliberately raises an exception every ~3 seconds causing HTTP 500 errors. This behavior is intentional for testing but causes alerts in production.

Changes Made:

• Modified the /ping endpoint to only raise the exception if the environment variable ENV is not set to "prod".

Rationale:

This change disables the intentional exception in production environments, preventing unnecessary 500 errors and alert noise. It preserves the testing behavior for non-production environments. Make sure to set ENV=prod in production deployments.