Bump protobufjs and firebase-admin

Bumps [protobufjs](https://github.com/protobufjs/protobuf.js) and [firebase-admin](https://github.com/firebase/firebase-admin-node). These dependencies needed to be updated together.

Updates `protobufjs` from 7.2.4 to 7.5.3
- [Release notes](https://github.com/protobufjs/protobuf.js/releases)
- [Changelog](https://github.com/protobufjs/protobuf.js/blob/master/CHANGELOG.md)
- [Commits](protobufjs/protobuf.js@protobufjs-v7.2.4...protobufjs-v7.5.3)

Updates `firebase-admin` from 11.11.1 to 13.6.0
- [Release notes](https://github.com/firebase/firebase-admin-node/releases)
- [Changelog](https://github.com/firebase/firebase-admin-node/blob/master/CHANGELOG.md)
- [Commits](firebase/firebase-admin-node@v11.11.1...v13.6.0)

---
updated-dependencies:
- dependency-name: protobufjs
  dependency-version: 7.5.3
  dependency-type: indirect
- dependency-name: firebase-admin
  dependency-version: 13.6.0
  dependency-type: indirect
...

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

Author: dependabot[bot]