Bump undici in the non-breaking-changes group across 1 directory

Bumps the non-breaking-changes group with 1 update in the / directory: [undici](https://github.com/nodejs/undici).


Updates `undici` from 6.15.0 to 6.18.0
- [Release notes](https://github.com/nodejs/undici/releases)
- [Commits](nodejs/undici@v6.15.0...v6.18.0)

---
updated-dependencies:
- dependency-name: undici
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: non-breaking-changes
...

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

package.json

@@ -19,7 +19,7 @@
     "make-coverage-badge": "^1.2.0",
     "nock": "^13.5.4",
     "prettier": "^3.2.5",
-    "undici": "^6.15.0"
+    "undici": "^6.18.0"
   },
   "scripts": {
     "all": "npm run format && npm run lint && npm run prepare && npm run test && npm run coverage-badge",