external CI (at least) has broken virtiofsd

[cgwalters]

In coreos/bootupd#1041 we saw

09:40:00  Running: buildah build --security-opt=label=disable --cap-add=all --device /dev/fuse --pull=newer --layers=true --build-arg-file build-args.conf -v /home/jenkins/agent/workspace/bootupd_PR-1041/tmp/build-with-buildah/src:/run/src --build-arg VERSION=43.20251214.dev.0 --label org.opencontainers.image.source=https://github.com/coreos/fedora-coreos-config --label org.opencontainers.image.revision=13a1fd7d83f5943108b1f9055b1eba857e77331f --label fedora-coreos.stream=testing-devel --annotation fedora-coreos.stream=testing-devel -v /home/jenkins/agent/workspace/bootupd_PR-1041/overrides:/src/overrides --tag containers-storage:localhost/fedora-coreos:43.20251214.dev.0 .
09:40:00  Formatting 'cache2.qcow2.tmp', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=53687091200 lazy_refcounts=off refcount_bits=16
09:40:12  [2025-12-17T14:40:12Z ERROR virtiofsd] can't apply the child capabilities: failed to sync capabilities with the kernel
09:40:13  qemu-system-x86_64: -chardev socket,id=virtiofschar0,path=/var/tmp/mantle-qemu4127580494/virtiofsd-0.sock: Failed to connect to '/var/tmp/mantle-qemu4127580494/virtiofsd-0.sock': Connection refused
09:40:45  Error: failed to establish qmp connection: dial unix /var/tmp/mantle-qemu4127580494/qmp-1765982412253121462.sock: connect: connection refused
09:40:45  2025-12-17T14:40:42Z cli: failed to establish qmp connection: dial unix /var/tmp/mantle-qemu4127580494/qmp-1765982412253121462.sock: connect: connection refused
09:40:45  fatal: Failed to run 'kola qemuexec'
09:40:45  failed to execute cmd-build: exit status 1
script returned exit code 1