Turbopack: Remove `non_operation_vc_strongly_consistent` feature usage from next-api (#85874)
This feature exists because we have some tests that aren't using the proper `OperationVc` APIs yet. It's documented that it should not be used in new code: https://github.com/search?q=repo%3Avercel%2Fnext.js%20non_operation_vc_strongly_consistent&type=code
This feature usage was added for some HMR benchmarks which were later removed. I added a comment to that PR here: https://github.com/vercel/next.js/pull/80219#discussion_r2143787319 (but it was after the PR merged)
The feature lets you strongly-consistently read or resolve a normal `Vc`. This API predates the `OperationVc` type, and is a footgun because if the `Vc` is already resolved, there's no meaningful way to read or resolve it with strong consistency.