This reverts commit 09b06657.

Reason for revert: Failures in TSan future: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Linux64%20TSAN%20-%20no-concurrent-marking/4731/overview

Original change's description:
> [Turboprop] Turboprop is the future.
>
> Enable --turboprop in the --future config.
>
> BUG=v8:9684
>
> Change-Id: I405832c2ef0e1b80200a8b8090d7672461cd9e00
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3035762
> Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
> Reviewed-by: Mythri Alle <mythria@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#75779}

Bug: v8:9684
Change-Id: I4ae2a51174565b3e773f4b5cb0f0cb652ca20111
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3035776
Auto-Submit: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#75781}