When is the reactivity dependencyMap cleaned up?

[stam]

In order to know when to rerender components, Vue's reactivity system keeps track of what reactive effects (like the render function of components) are dependent on which reactive state. It stores these reactivity "dependencies" in a WeakMap.

I assume that when a component is unmounted, the reactivity dependencies leading to that component are not needed anymore. But I can't seem to find that cleanup anywhere.

I created a codesandbox for it to better illustrate what I mean: https://codesandbox.io/s/vue-depsmap-cleanup-wdq7rf?file=/src/Red.vue

This app contains 2 “pages”: the red page and the blue page. When you press the "change page" button a lot I would assume that Vue cleans up the reactivity dependencies of the state from the Red component. It does not need to know that it should rerender the Red component if the Red state changes when the Red component is not mounted anymore. But if I create a breakpoint in the reactivity file at line 499, I see that the targetMap is growing and growing.

My question is: when is this targetMap being cleaned up? If it is only being cleaned up if the object itself is garbage collected,
how is this not causing massive memory leaks in apps with centralised stores?