Add Rekor APK decompression fix references

[cookesan]

Adds Rekor APK decompression fix references to GHSA-47q9-m4ww-924m.

Audit refresh, July 8, 2026:

• Confirmed the live PR is open, ready for review, merge-clean, and the visible advisory check is green.
• Rechecked the merge-base diff: exactly one advisory JSON file changes (advisories/github-reviewed/2026/06/GHSA-47q9-m4ww-924m/GHSA-47q9-m4ww-924m.json), JSON parses, git diff --check passes, and the exact-head worktree is clean.
• Revalidated the added public references in the diff; all resolve through their source site or registry.

[cookesan]

Maintainer audit: this only expands the reference set for the Rekor APK decompression advisory. sigstore/rekor#2831 is merged, commit 759b98e2a7c39ea9779b6a51299c5f0f987f8802 resolves, release tag v1.5.2 resolves, and github.com/sigstore/rekor@v1.5.2 is available from the Go proxy. The advisory JSON parses, the committed diff passes git diff --check, the PR is merge-clean, and advisory processing is successful. No package, affected range, severity, or database metadata is changed.