bug#67829: qtwebengine new failure on i686

[Maxim Cournoyer <maxim.cournoyer@gmail.com>]

Hello,

qtwebengine was marked as newly failing by Cuirass on Berlin, as a
result to the xorg-server update in
https://git.savannah.gnu.org/cgit/guix.git/commit/?id=8083c7abbf3a346162fcc4b8d5aa50555c0f3179.

--8<---------------cut here---------------start------------->8---
v8_use_external_startup_data=false
CMake Error at /tmp/guix-build-qtwebengine-6.5.2.drv-0/qtwebengine-everywhere-src-6.5.2/cmake/Gn.cmake:75 (message):
  

  -- GN FAILED

  ERROR at //BUILD.gn:1652:1: Assertion failed.

  assert(

  ^-----

  'target_cpu=x86' is not supported for 'target_os=linux'.  Consider omitting
  'target_cpu' (default) or using 'target_cpu=x64' instead.

  See //BUILD.gn:1653:5:

      is_valid_x86_target || target_cpu != "x86" || v8_target_cpu == "arm",
      ^-------------------------------------------------------------------

  This is where it was set.

  1

ninja: build stopped: subcommand failed.
--8<---------------cut here---------------end--------------->8---

I don't see how the two would be related, but I've CC'd John in case
they'd have some hunch.

Perhaps some non-deterministic issue with the 'gn' build system?  It had
succeeded here: https://ci.guix.gnu.org/build/2803939/details about a
week ago.

-- 
Thanks,
Maxim