Bump undici from 6.19.8 to 6.21.1

Bumps [undici](https://github.com/nodejs/undici) from 6.19.8 to 6.21.1.
- [Release notes](https://github.com/nodejs/undici/releases)
- [Commits](nodejs/undici@v6.19.8...v6.21.1)

---
updated-dependencies:
- dependency-name: undici
  dependency-type: direct:production
...

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

packages/plugin-hardhat/package.json

@@ -43,7 +43,7 @@
     "debug": "^4.1.1",
     "ethereumjs-util": "^7.1.5",
     "proper-lockfile": "^4.1.1",
-    "undici": "^6.11.1"
+    "undici": "^6.21.1"
   },
   "peerDependencies": {
     "@nomicfoundation/hardhat-ethers": "^3.0.0",

yarn.lock

@@ -6464,10 +6464,10 @@ undici@^5.14.0:
   dependencies:
     "@fastify/busboy" "^2.0.0"
 
-undici@^6.11.1:
-  version "6.19.8"
-  resolved "https://registry.yarnpkg.com/undici/-/undici-6.19.8.tgz#002d7c8a28f8cc3a44ff33c3d4be4d85e15d40e1"
-  integrity sha512-U8uCCl2x9TK3WANvmBavymRzxbfFYG+tAu+fgx3zxQy3qdagQqBLwJVrdyO1TBfUXvfKveMKJZhpvUYoOjM+4g==
+undici@^6.21.1:
+  version "6.21.1"
+  resolved "https://registry.yarnpkg.com/undici/-/undici-6.21.1.tgz#336025a14162e6837e44ad7b819b35b6c6af0e05"
+  integrity sha512-q/1rj5D0/zayJB2FraXdaWxbhWiNKDvu8naDT2dl1yTlvJp4BLtOcp2a5BvgGNQpYYJzau7tf1WgKv3b+7mqpQ==
 
 unfetch@^4.2.0:
   version "4.2.0"