Precompiled 2025-07-18-5d94fa5

Record a metric for staleness of query invalidations (#39205)

This PR plumbs the timestamp of the invalidating write, if known, all the way through `extend_validity`.
Then, in the sync worker, we can measure the real time delay between the write and the subscribed re-executing query.
We can monitor this to make sure it is a reasonable value.

GitOrigin-RevId: 2210b600a96656f489e685553a49f11abfda7fcd