Prepare for 5.15.7: adapt test
According to https://bugreports.qt.io/browse/QTBUG-83081, the bug has been fixed in 5.15.7, so don't let the tests fail if using that version
According to https://bugreports.qt.io/browse/QTBUG-83081, the bug has been fixed in 5.15.7, so don't let the tests fail if using that version