Backend returns inconsistent values

[jbonisteel]

From Slack: https://openobservatory.slack.com/archives/GKGRFHXT7/p1730227093226719

**_intl which is usually an empty object, can be null some times.
https://run.ooni.org/api/v2/oonirun/links/10030 || values set to null
https://run.ooni.org/api/v2/oonirun/links/10028 || values set as empty objects.
We should maybe always return the empty objects.

[hellais]

We explicitly support None as a valid type of _intl: https://github.com/ooni/backend/blob/master/ooniapi/services/oonirun/src/oonirun/routers/v2.py#L96.

Changing this to be only an empty object would be a non-trivial amount of work as we would have to migrate all the existing OONI Run links to the new format and probably change the DB schema. Is this currently breaking clients?

[jbonisteel]

I checked into this more, it is not breaking clients but may impact some power users (surfshark, for ex)