The main open questions here are:

• Should we add pre-made prometheus queries and links for tokio runtime metrics? Which ones?
• Where should this section be added, since it's a "global" metric not linked to a function?
• Is the current feature set to trigger the option ok?

I also probably want to add at least a compile test in the CI to check that the feature flags work correctly

I think we can close this PR for now. We may want to revisit automatically collecting runtime metrics in the future.