Bump protobufjs from 8.0.3 to 8.4.0 in /src/Elastic.Documentation.Site

Bumps [protobufjs](https://github.com/protobufjs/protobuf.js) from 8.0.3 to 8.4.0.
- [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-v8.0.3...protobufjs-v8.4.0)

---
updated-dependencies:
- dependency-name: protobufjs
  dependency-version: 8.4.0
  dependency-type: indirect
...

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Author: dependabot[bot]