Devel docs on website reloading

Today, we build and update the docs on
https://www.postgresql.org/docs/devel/ are rebuilt and deployed by the
buildfarm automatically every 4 hours.

If there are no changes at all made to the docs, they are *still*
kicked out of all caches and the search indexes are rebuilt, because
we change the "time of load" at the top of the page.

It would be trivial to change this so that it only actually updates
pages if they have been changed.

However, the result of that is that the timestamp on the docs pages
will then stay unchanged until there is an actual commit that has made
a docs change. (It would still reload the full set of docs at once,
just skip them completely when there are no changes at all, so the
value between different pages would remain unchanged)

I think that's a good change, and I don't really see a usecase where
having that date update every 4 hours "just because", but before
making a change I wanted to throw it out here and see if someone else
has a usecase where the current behaviour would be better?

--
Magnus Hagander
Me: https://www.hagander.net/
Work: https://www.redpill-linpro.com/