deps(dev): bump sinon from 19.0.5 to 21.0.0 (#432)

Bumps [sinon](https://github.com/sinonjs/sinon) from 19.0.5 to 21.0.0.
- [Release notes](https://github.com/sinonjs/sinon/releases)
- [Changelog](https://github.com/sinonjs/sinon/blob/main/docs/changelog.md)
- [Commits](https://github.com/sinonjs/sinon/commits)

---
updated-dependencies:
- dependency-name: sinon
  dependency-version: 21.0.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

packages/ipfs-unixfs-exporter/package.json

@@ -168,7 +168,7 @@
     "it-to-buffer": "^4.0.7",
     "merge-options": "^3.0.4",
     "readable-stream": "^4.5.2",
-    "sinon": "^19.0.2",
+    "sinon": "^21.0.0",
     "uint8arrays": "^5.1.0",
     "wherearewe": "^2.0.1"
   },