refactor(backend): migrate from deprecated on_event to lifespan context manager#1238

NPuhlmann wants to merge 2 commits intolangflow-ai:mainlangflow-ai/openrag:mainfrom

NPuhlmann:refactor/migrate-to-fastapi-lifespanNPuhlmann/openrag:refactor/migrate-to-fastapi-lifespanCopy head branch name to clipboard