Revert "Reland "Turn on v8_enable_virtual_memory_cage for Chromium builds""

This reverts commit 75dd3600.

Reason for revert: Breaks V8 roll, failure on Fuchsia: https://ci.chromium.org/ui/p/chromium/builders/try/fuchsia_arm64/964489/overview

Original change's description:
> Reland "Turn on v8_enable_virtual_memory_cage for Chromium builds"
>
> This is a reland of 4fb3eae7
>
> crrev.com/c/3202002 fixed the Chromium build issue.
>
> Original change's description:
> > Turn on v8_enable_virtual_memory_cage for Chromium builds
> >
> > This CL enables the virtual memory cage at compile time by default for
> > Chromium builds on x64 and arm64. However, the cage will only be used at
> > runtime if the correpsonding Chromium feature is enabled as well.
> >
> > Bug: chromium:1218005
> > Change-Id: I5a452d299ac950f8ec0f741f6b9a153e57b2a666
> > Cq-Include-Trybots: luci.v8.try:v8_linux64_heap_sandbox_dbg_ng
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3200081
> > Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> > Commit-Queue: Samuel Groß <saelo@chromium.org>
> > Cr-Commit-Position: refs/heads/main@{#77212}
>
> Bug: chromium:1218005
> Change-Id: I32b1a4088ca44827ca4f76b5d19b8138875bfc97
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3204950
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Commit-Queue: Samuel Groß <saelo@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#77229}

Bug: chromium:1218005
Change-Id: I90f3d5e2878f429125c2a2ebde1105a4116c8d1f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3205895
Auto-Submit: Maya Lekova <mslekova@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/main@{#77236}

BUILD.gn

@@ -472,13 +472,6 @@ if (build_with_chromium && v8_current_cpu == "arm64" &&
   v8_control_flow_integrity = true
 }
 
-# Enable the virtual memory cage on 64-bit Chromium builds.
-if (build_with_chromium &&
-    (v8_current_cpu == "arm64" || v8_current_cpu == "x64")) {
-  # The cage is incompatible with lsan.
-  v8_enable_virtual_memory_cage = !is_lsan
-}
-
 assert(!v8_disable_write_barriers || v8_enable_single_generation,
        "Disabling write barriers works only with single generation")