ISO: give bootc-image-builder the buildah containers storage (now required)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.forgejo/workflows/build-iso.yml

@@ -34,6 +34,7 @@ jobs:
           docker volume create kamos-bib-output
           docker run --rm --privileged \
             -v kamos-bib-output:/output \
+            -v kamos-buildah:/var/lib/containers \
             quay.io/centos-bootc/bootc-image-builder:latest \
             --type anaconda-iso \
             "${REGISTRY_HOST}/${OWNER}/${{ inputs.variant }}:stable"