build(deps-dev): bump whatwg-fetch from 3.6.19 to 3.6.20 (#444)

Bumps [whatwg-fetch](https://github.com/github/fetch) from 3.6.19 to 3.6.20.
- [Release notes](https://github.com/github/fetch/releases)
- [Changelog](https://github.com/JakeChampion/fetch/blob/main/CHANGELOG.md)
- [Commits](JakeChampion/fetch@v3.6.19...v3.6.20)

---
updated-dependencies:
- dependency-name: whatwg-fetch
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -64,7 +64,7 @@
     "prettier": "^3.2.5",
     "ts-jest": "^29.1.2",
     "typescript": "^5.4.4",
-    "whatwg-fetch": "^3.6.19"
+    "whatwg-fetch": "^3.6.20"
   },
   "jest": {
     "preset": "ts-jest",