Bump undici and firebase in /firestore

Removes [undici](https://github.com/nodejs/undici). It's no longer used after updating ancestor dependency [firebase](https://github.com/firebase/firebase-js-sdk). These dependencies need to be updated together.


Removes `undici`

Updates `firebase` from 10.14.1 to 11.2.0
- [Release notes](https://github.com/firebase/firebase-js-sdk/releases)
- [Changelog](https://github.com/firebase/firebase-js-sdk/blob/main/CHANGELOG.md)
- [Commits](https://github.com/firebase/firebase-js-sdk/compare/[email protected]@11.2.0)

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

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