Utilities/Sphinx: Tell linkcheck to not treat timeouts as broken

Sphinx 7.3 warns:

    sphinx/builders/linkcheck.py:86: RemovedInSphinx80Warning:
    The default value for 'linkcheck_report_timeouts_as_broken'
    will change to False in Sphinx 8, ...

Configure that behavior explicitly.

Utilities/Sphinx/conf.py.in

@@ -103,3 +103,5 @@ linkcheck_allowed_redirects = {
     r'https://openjdk\.java\.net/jeps/313': r'https://openjdk\.org:443/jeps/313',
     r'https://www\.sphinx-doc\.org': r'https://www\.sphinx-doc\.org/en/master/',
 }
+
+linkcheck_report_timeouts_as_broken = False