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.

images/fedora-cosmic/files/finalize.d/50-packages

@@ -0,0 +1,12 @@
+#!/bin/bash
+# Runs in the target root during `rpm-ostree compose image` (edition 2024
+# finalize.d hook). Records the installed package list next to the treefile so
+# build.sh can hand it to release.sh without having to mount the built image.
+set -euo pipefail
+
+if [[ -z "${RPMOSTREE_WORKDIR:-}" ]]; then
+  echo "RPMOSTREE_WORKDIR not set, skipping package list" >&2
+  exit 0
+fi
+
+rpm -qa --root "${PWD}" --qf '%{NAME} %{EVR}\n' | sort > "${RPMOSTREE_WORKDIR}/packages-current.txt"