Add a link to libxml2's CVE-2024-34459 NVD entry.

Author: postmodern

gems/nokogiri/GHSA-r95h-9x8f-r3f7.yml

@@ -35,3 +35,4 @@ related:
     - https://gitlab.gnome.org/GNOME/libxml2/-/commit/2876ac53
     - https://gitlab.gnome.org/GNOME/libxml2/-/issues/720
     - https://github.com/advisories/GHSA-r95h-9x8f-r3f7
+    - https://nvd.nist.gov/vuln/detail/CVE-2024-34459