hydron: mark as vulnerable to CVE-2023-4863

pkgs/servers/hydron/default.nix

···
     homepage = "https://github.com/bakape/hydron";
     description = "High performance media tagger and organizer";
     license = with licenses; [ lgpl3Plus ];
+    knownVulnerabilities = [ "CVE-2023-4863" ];  # Via https://github.com/chai2010/webp dep
     maintainers = with maintainers; [ Madouura ];
   };
 }