Use virtio-net and virtio-gpu on arm64 again

The base image now carries the VirtIO drivers, which restores the 2304x1440
display that ramfb had lost.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

run-windows11.py

@@ -97,8 +97,8 @@ scripts on the desktop). If the disk exists, start Windows normally, without the
 seed ISO.
 Make the base image once with vm-images/build-windows-base.sh; it installs
 Windows from the ISO and generalizes the result. The base image contains only
-Windows (no account, no SSH, no VirtIO or other hardware-specific drivers), so
-the devices in qemu/windows11 are ones Windows has inbox drivers for.
+Windows plus the VirtIO drivers (no account, no SSH, no other
+hardware-specific drivers).
 The VM hardware (accelerator, memory, CPUs, drives, devices) is defined in
 qemu/windows11/config.ini, which is rendered to qemu.ini in the state directory and
 loaded with QEMU's -readconfig, followed by qemu/windows11/<os>-<arch>.ini (os is linux or darwin, arch is amd64 or arm64, chosen from the host system and