Consider in-construction keys as live during the final GC pause.

Bug: chromium:1259587
Change-Id: Ia8c05923db6e5827b68b17a51561fbc8b2c4b467
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3221153
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77386}