Let a page on a client wiki add a tracking category if the linked item is missing a P1472 statement.
Then, when a P1472 is added to the item, the page should be re-renders, but it is not - it still shows the category.
When purging the page, it is re-rendered, and no longer shows the category; however, the category page still lists the page.
Expected behavior: after the P1472 statement is added to the wikidata item, the page on the client wiki should be re-rendered, and should no longer be listed on the category page.
Hypothesis: The RefreshLinksJob scheduled by PageUpdater ends up using a cached ParserOutput, instead of re-parsing the page. Puring updates the parser cache, but doesn't update the categorylinks table. A null edit is needed to trigger that.