Add No Runner Agent found msg to UI
What does this MR do and why was it needed?
Small update: when a runner agent is deleted, the runner agent detail page now displays a 'no runner agent found' message in the UI instead of throwing an error.
What's the best way to test this MR?
Go to the detail page of a runner agent. Delete the runner agent (via GraphiQL). After refreshing the runner agent detail page, the UI should display a message that the runner agent was not found.