chore(deps): bump protobufjs and firebase-admin in /functions (#501)

* chore(deps): bump protobufjs and firebase-admin in /functions

Bumps [protobufjs](https://github.com/protobufjs/protobuf.js) to 7.5.3 and updates ancestor dependency [firebase-admin](https://github.com/firebase/firebase-admin-node). These dependencies need to be updated together.


Updates `protobufjs` from 7.2.3 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-v7.2.3...protobufjs-v7.5.3)

Updates `firebase-admin` from 11.7.0 to 13.4.0
- [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@v11.7.0...v13.4.0)

---
updated-dependencies:
- dependency-name: protobufjs
  dependency-version: 7.5.3
  dependency-type: indirect
- dependency-name: firebase-admin
  dependency-version: 13.4.0
  dependency-type: direct:production
...

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

* Drop `firebase-admin` down a revision

---------

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

Author: dependabot[bot]