[REGRESSION] Cloud Hypervisor crashes when guest writes to VSOCK

This notably happens when an application that uses portals starts up and the org.freedesktop.impl.portal.desktop.spectrum D-Bus service is activated. Already fixed upstream in Cloud Hypervisor: https://github.com/cloud-hypervisor/cloud-hypervisor/pull/7477 Proposed a backport in Nixpkgs: https://github.com/NixOS/nixpkgs/pull/464618