mjsunit/compiler/deopt-pretenure.js is flaky due to --gc-interval in
some variants.
The flag can cause a variable to be promoted to old space before the
test can force allocation site pretenuring for that variable, which is
essential for the test case.

Bug: v8:12652
Change-Id: If7239deaa3026bb781d3ee96df28a1bbf3a5b6f1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3488371
Auto-Submit: Patrick Thier <pthier@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79275}