It would be valuable to emit stats from ipoid to read from grafana in order to check on the state of the service as we have little insight into how it's been doing (eg. it'd be nice to know why updates now take ~24 hours and if we can continue to expect that time to increase or if we can do anything to reduce it). To avoid overloading the main import cron job, we should split stats generation and emit into its own function and job.

This could support tickets like T383898: Instrument data point to view status of `tunnels.anonymous` and T375371: Expose metric for last successful ipoid import date