Add Hugo IPv4 SSRF fix references

[cookesan]

Adds Hugo IPv4 SSRF fix references to GHSA-r46f-3rpw-hxrv.

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-r46f-3rpw-hxrv/GHSA-r46f-3rpw-hxrv.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 Hugo IPv4 SSRF advisory. Commit a00b5c72ac57afe26df6688ece3ca544a56df372 resolves, release tag v0.163.1 resolves, and github.com/gohugoio/hugo@v0.163.1 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.