Add regression test for #30172 (#30198)

The issue reported in #30172 was fixed with #29823. The PR also added
the test [`should resolve deduped objects that are themselves
blocked`](https://github.com/facebook/react/blob/6d2a97a7113dfac2ad45067001b7e49a98718324/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOMBrowser-test.js#L348-L393),
which tests a similar scenario. However, the existing test would have
also succeeded before applying the changes from #29823. Therefore, I
believe it makes sense to add an additional test `should resolve deduped
objects in nested children of blocked models`, which does not succeed
without #29823, to prevent regressions.