Bump protobufjs, firebase-admin and firebase-tools in /functions

Bumps [protobufjs](https://github.com/protobufjs/protobuf.js) to 7.6.1 and updates ancestor dependencies [protobufjs](https://github.com/protobufjs/protobuf.js), [firebase-admin](https://github.com/firebase/firebase-admin-node) and [firebase-tools](https://github.com/firebase/firebase-tools). These dependencies need to be updated together.


Updates `protobufjs` from 6.10.2 to 7.6.1
- [Release notes](https://github.com/protobufjs/protobuf.js/releases)
- [Changelog](https://github.com/protobufjs/protobuf.js/blob/protobufjs-v7.6.1/CHANGELOG.md)
- [Commits](protobufjs/protobuf.js@v6.10.2...protobufjs-v7.6.1)

Updates `firebase-admin` from 8.13.0 to 13.10.0
- [Release notes](https://github.com/firebase/firebase-admin-node/releases)
- [Changelog](https://github.com/firebase/firebase-admin-node/blob/main/CHANGELOG.md)
- [Commits](firebase/firebase-admin-node@v8.13.0...v13.10.0)

Updates `firebase-tools` from 9.10.0 to 15.19.0
- [Release notes](https://github.com/firebase/firebase-tools/releases)
- [Commits](firebase/firebase-tools@v9.10.0...v15.19.0)

---
updated-dependencies:
- dependency-name: protobufjs
  dependency-version: 7.6.1
  dependency-type: indirect
- dependency-name: firebase-admin
  dependency-version: 13.10.0
  dependency-type: direct:production
- dependency-name: firebase-tools
  dependency-version: 15.19.0
  dependency-type: direct:production
...

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Author: dependabot[bot]