Per the parent task, update the version of Vue to match the version we use in the rest of Wikibase - 3.3.9
There used to be a test that failed as soon as the Termbox Vue version doesn't match the mediawiki Vue version. That test was temporarily disabled (in 2021) because determining the version became tricky. We should decide whether we want to do anything about that test or just remove it. See T297381 and comments, specifically T297381#9370727.