ci: generate package list during compose via finalize.d

Avoid mounting the built image with buildah (ran out of disk); the
finalize.d hook records the rpm list next to the treefile and release.sh
consumes it directly.

.gitea/workflows/build.yaml

@@ -46,7 +46,7 @@ jobs:
         run: |
           set -xeuo pipefail
           dnf install -y nodejs jq curl git createrepo_c
-          dnf install -y skopeo buildah
+          dnf install -y skopeo
           dnf install -y cosign || true
           if ! command -v cosign >/dev/null; then
             case "$(uname -m)" in
@@ -114,5 +114,5 @@ jobs:
           RELEASE_TOKEN: ${{ secrets.RELEASE_TOKEN }}
         run: |
           buildid="$(cat .buildid)"
-          oci="build/${IMAGE}-${DISTRO}-${ARCH}/${IMAGE}-${DISTRO}-${ARCH}.ociarchive"
-          ./release.sh "${IMAGE}" "${DISTRO}" "${buildid}" "${oci}"
+          pkgs="build/${IMAGE}-${DISTRO}-${ARCH}/packages-current.txt"
+          ./release.sh "${IMAGE}" "${DISTRO}" "${buildid}" "${pkgs}"