Janeway is a science officer by trade. Maybe she didn't even take this test.
Kathy had to take the test as soon as she decided to take th command track whether that was at the academy or after being influenced by the awesomeness of serving under captain Owen Paris and wanting to be just like him... Not that her father wasn't an admiral too that science was just the route she was taking to command, since her family and the memory of her father had expectations of her career.
Either at the academy, or a holodeck turned into an academy later on her career (like Deanna) there were prerequisites and qualifications which Janeway couldn't side step if she was to get her fourth pip without fluffing the paperwork or cheating.
Spock was captain of the Enterprise in Wrath of Khan and he'd never taken the Kobayashi Maru.
Reverse continuity says he used to program the test, but he still never took it.