Address review of the version generator (hack/update-versions.sh):

- Fetch tags with `skopeo list-tags` (registry v2 /tags/list) instead of
  the Docker Hub v2 API, whose anonymous pagination caps at 1000 entries
  and then returns an error page with no `.results`, silently truncating
  the list so the frozen 24.9.2.42 fell outside the window and the run
  failed. skopeo is already in build-deps and is how the sibling
  generators (postgres, redis, mongodb, opensearch, kubernetes) fetch.
- Make a frozen default tag missing from the registry a hard error
  instead of silently falling back to a newer patch, which would move
  the default image for existing installs.
- Restore 0644 on the regenerated files (mktemp's 0600 survived the mv).
- Exclude /hack from the chart tarball via .helmignore.
- Refresh files/versions.yaml: v25.8 -> 25.8.32.4, the true latest 25.8
  patch now visible with the complete tag list.
- bats: add a missing-frozen-tag hard-error case and make the atomicity
  test reach the resolution phase after a valid default rather than
  failing at the default-in-set check.

Signed-off-by: Alexey Artamonov <[email protected]>
(cherry picked from commit e707475)
Signed-off-by: Myasnikov Daniil <[email protected]>
Assisted-By: LLM