Bump tar-stream from 3.1.7 to 3.1.8 in /plugins/system-utility

Bumps [tar-stream](https://github.com/mafintosh/tar-stream) from 3.1.7 to 3.1.8.
- [Commits](mafintosh/tar-stream@v3.1.7...v3.1.8)

---
updated-dependencies:
- dependency-name: tar-stream
  dependency-version: 3.1.8
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Author: dependabot[bot]