Bump undici from 6.19.2 to 6.21.1

Bumps [undici](https://github.com/nodejs/undici) from 6.19.2 to 6.21.1.
- [Release notes](https://github.com/nodejs/undici/releases)
- [Commits](nodejs/undici@v6.19.2...v6.21.1)

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

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package-lock.json

@@ -81,7 +81,7 @@
     "tstyche": "^3.0.0",
     "typescript": "^5.3.3",
     "typescript-eslint": "^7.13.0",
-    "undici": "^6.19.2"
+    "undici": "^6.21.1"
   },
   "overrides": {
     "d3-color": "3.1.0",