gitlab-ci.d/crossbuilds: Drop the i386 system emulation job

gitlab-ci.d/crossbuilds: Drop the i386 system emulation job

Hardly anybody still uses 32-bit x86 environments for running QEMU with
full system emulation, so let's stop wasting our scarce CI minutes with
this job.

(There are still the 32-bit MinGW and TCI jobs around for having
some compile test coverage on 32-bit)

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Message-Id: <20230306084658.29709-4-thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>