.gitlab-ci.d/windows.yml: Drop msys2-32bit job

.gitlab-ci.d/windows.yml: Drop msys2-32bit job

MSYS2 is dropping support for 32-bit Windows.  This shows up for us
as various packages we were using in our CI job no longer being
available to install, which causes the job to fail.  In commit
8e31b744fdf we dropped the dependency on libusb and spice, but the
dtc package has also now been removed.

For us as QEMU upstream, "32 bit x86 hosts for system emulation" have
already been deprecated as of QEMU 8.0, so we are ready to drop them
anyway.

Drop the msys2-32bit CI job, as the first step in doing this.

This is cc'd to stable, because this job will also be broken for CI
on the stable branches.  We can't drop 32-bit support entirely there,
but we will still be covering at least compilation for 32-bit Windows
via the cross-win32-system job.

Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20240220165602.135695-1-peter.maydell@linaro.org