ci: use host network for Buildah image build

.woodpecker/release-backend.yml

@@ -49,5 +49,5 @@ steps:
       - printf '%s' "$ZOT_PASSWORD" | buildah login --tls-verify=false "$ZOT_REGISTRY" --username "$ZOT_USERNAME" --password-stdin
       - trap 'buildah logout "$ZOT_REGISTRY" >/dev/null 2>&1 || true' EXIT
       - image="$ZOT_REGISTRY/justme/webdrop-api:$release_tag"
-      - buildah bud --format docker --platform linux/amd64 --tag "$image" --file server/Dockerfile .
+      - buildah bud --network host --format docker --platform linux/amd64 --tag "$image" --file server/Dockerfile .
       - buildah push --tls-verify=false "$image" "docker://$image"