Bump @grpc/grpc-js and firebase

Bumps [@grpc/grpc-js](https://github.com/grpc/grpc-node) to 1.9.15 and updates ancestor dependency [firebase](https://github.com/firebase/firebase-js-sdk). These dependencies need to be updated together.


Updates `@grpc/grpc-js` from 1.7.3 to 1.9.15
- [Release notes](https://github.com/grpc/grpc-node/releases)
- [Commits](https://github.com/grpc/grpc-node/compare/@grpc/grpc-js@1.7.3...@grpc/grpc-js@1.9.15)

Updates `firebase` from 9.23.0 to 11.6.0
- [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/firebase@9.23.0...firebase@11.6.0)

---
updated-dependencies:
- dependency-name: "@grpc/grpc-js"
  dependency-version: 1.9.15
  dependency-type: indirect
- dependency-name: firebase
  dependency-version: 11.6.0
  dependency-type: direct:production
...

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Author: dependabot[bot]