Turbo tasks: Reuse aggregation context and apply queued updates (#7847)
This resolves an issue that caused Turbopack to panic with
https://github.com/vercel/turbo/blob/04e2a9f0cb9439913975a325ce3eb59b46380ff8/crates/turbo-tasks-memory/src/task/aggregation.rs#L211
When marking a task dirty:
- Reuse the aggregation context instead of creating
- Apply queued updates
Closes PACK-2846