chore: catalogue new Splice versions

[github-actions]

Auto-generated by .github/workflows/refresh-versions.yml.

New Splice tags added to internal/splice/versions.json:

0.9.0

Each entry was added by scripts/add-splice-version.sh, which:

1. Resolves the tag → commit SHA via the GitHub REST API
   (peeling annotated tags).
2. Downloads the source archive at that commit.
3. Computes the deterministic ContentSHA of the extracted
   cluster/compose/localnet/ subtree.

Reviewer checklist:

• Confirm each new tag corresponds to a release we want
  to support (not a pre-release artifact).
• Bump latest_alias in versions.json if the newest
  catalogued tag should be the default latest.
• Consider scheduling an integration run against the
  newest entry before merging.