Add linkify-it fix references

[cookesan]

Adds linkify-it fix references to GHSA-22p9-wv53-3rq4.

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-22p9-wv53-3rq4/GHSA-22p9-wv53-3rq4.json), JSON parses, git diff --check passes, and the exact-head worktree is clean.
• Revalidated the added public references and package-version evidence in the diff; all resolve through their source site or registry.

[cookesan]

Rechecked this reference-only PR while keeping the open Advisory Database queue current.

• The patch only adds linkify-it fix commit and fixed tag references; it does not change affected ranges, package metadata, or severity.
• The commit resolves to 6be6d15e0641bf1daeaa977d500cabc743166159.
• The 5.0.1 tag reference resolves, matching the advisory fixed version.

No other advisory fields are changed.