Bump undici from 6.19.8 to 6.21.2 in /website

Bumps [undici](https://github.com/nodejs/undici) from 6.19.8 to 6.21.2.
- [Release notes](https://github.com/nodejs/undici/releases)
- [Commits](nodejs/undici@v6.19.8...v6.21.2)

---
updated-dependencies:
- dependency-name: undici
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

website/yarn.lock

@@ -13292,9 +13292,9 @@ __metadata:
   linkType: hard
 
 "undici@npm:^6.19.5":
-  version: 6.19.8
-  resolution: "undici@npm:6.19.8"
-  checksum: 10/19ae4ba38b029a664d99fd330935ef59136cf99edb04ed821042f27b5a9e84777265fb744c8a7abc83f2059afb019446c69a4ebef07bbc0ed6b2de8d67ef4090
+  version: 6.21.2
+  resolution: "undici@npm:6.21.2"
+  checksum: 10/9cd9ead22599c23aa2a7dfa5b80fa1491bebb294bf1dc64c9c0f90ea4ec8e272a4db2810e2565d65b952249f105523d2929d7cc951f88cf0a1f082143bae8d75
   languageName: node
   linkType: hard