Bump tar-fs in /plugins/gatsby-plugin-image-generator

Bumps [tar-fs](https://github.com/mafintosh/tar-fs) from 2.1.1 to 2.1.4.
- [Commits](mafintosh/tar-fs@v2.1.1...v2.1.4)

---
updated-dependencies:
- dependency-name: tar-fs
  dependency-version: 2.1.4
  dependency-type: indirect
...

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Author: dependabot[bot]