Reduce default QTRY_* timeout

As explained in QTBUG-81979 and its patches (in particular, this comment from the maintainer), 5 seconds (doubled by Qt Test, so effectively 10 seconds) is too long. For most tests, 1 second is plenty and would save developers a lot of time, especially for tests involving many QTRY_* checks where it's not clear which test is failing if the test was killed before the check finished (to avoid waiting the full 10 seconds).

Changing this in Qt 6 would break a lot of users' tests, so we should do it in Qt 7. After https://codereview.qt-project.org/c/qt/qtbase/+/648330, they can also increase the timeout with a one-liner for each test case if it's then too short.