Include `use-cache` test suite in the Cache Components tests (#81610)
We're splitting the test app routes between two root layouts, one for (partially) static pages that does not wrap its children in a Suspense boundary, and one for dynamic pages that adds a Suspense boundary above `body`, which opts those pages into fully dynamic rendering.
Two tests are expected to fail for now, because they revealed bugs related to revalidation, which will be fixed in follow-up PRs:
- https://github.com/vercel/next.js/pull/81611
- https://github.com/vercel/next.js/pull/81621
closes NAR-171