Bump protobufjs from 7.2.5 to 7.2.6 in /test/servers

Bumps [protobufjs](https://github.com/protobufjs/protobuf.js) from 7.2.5 to 7.2.6.
- [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-v7.2.5...protobufjs-v7.2.6)

---
updated-dependencies:
- dependency-name: protobufjs
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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