fix(release): recreate refs/remotes dropped by git on the Flatpak remote publish (#966)

* fix(release): recreate refs/remotes dropped by git on the Flatpak remote publish

The first real remote publish (v0.18.3) failed at
'flatpak build-update-repo --generate-static-deltas' with
'opendir(refs/remotes): No such file or directory'. ostree init creates
refs/remotes empty, git does not track empty dirs, and the site/repo
checked back out of gh-pages therefore lacks it — while delta generation
opens that dir unconditionally. mkdir -p it (and refs/mirrors) after the
copy. Also name the Snap Store review-queue blockage in its publish
error, so the fix (reject the stale upload on the dashboard, re-run)
surfaces on the job page.

* test(release): pin the refs/remotes mkdir before build-update-repo

---------

Co-authored-by: Jatin K Malik <jatinkrmalik@gmail.com>

.github/workflows/release.yml

@@ -684,6 +684,11 @@ jobs:
             mkdir -p "$repo"
             ostree --repo="$repo" init --mode=archive-z2
           fi
+          # git drops empty directories: a checked-out site/repo lacks
+          # refs/remotes and refs/mirrors, and `build-update-repo
+          # --generate-static-deltas` aborts with
+          # "opendir(refs/remotes): No such file or directory" without them.
+          mkdir -p "$repo/refs/remotes" "$repo/refs/mirrors"
           ls -la dist/*.flatpak
           for bundle in dist/*.flatpak; do
             flatpak build-import-bundle \
@@ -1092,6 +1097,10 @@ jobs:
             echo "::warning::Snap Store queued a human review (allow-installation). The .snap is on the GitHub Release."
             exit 0
           fi
+          if grep -F -q "Waiting for previous upload(s)" "$log"; then
+            echo "::error::Snap Store publish failed: an older upload is still in the review queue. Reject and remove it at https://dashboard.snapcraft.io/ (the upload page lists it), then re-run this job."
+            exit "$status"
+          fi
           echo "::error::Snap Store publish failed (exit $status) for a reason other than allow-installation review."
           exit "$status"