Set linkcheck_report_timeouts_as_broken to False in Sphinx<8

[stevepiercy]

Links of affected pages in Plone Documentation, if any.

No response

Description

A new feature was added in Sphinx 7.3, linkcheck_report_timeouts_as_broken.

We set a low timeout threshold to speed up linkcheck because we have 1832 external links. This results in slightly more timeouts of shorter duration. Often the timeouts last only a few minutes, and go back to normal.

We should set this value to False now.

When we move to Sphinx 8, then we can remove this setting, as the default changes to False.

Leave this issue open until we migrate to Sphinx 8, depending on the parent themes' adoption.