Bump mikey179/vfsstream from 1.6.11 to 1.6.12

Bumps [mikey179/vfsstream](https://github.com/bovigo/vfsStream) from 1.6.11 to 1.6.12.
- [Release notes](https://github.com/bovigo/vfsStream/releases)
- [Changelog](https://github.com/bovigo/vfsStream/blob/v1.6.12/CHANGELOG.md)
- [Commits](bovigo/vfsStream@v1.6.11...v1.6.12)

---
updated-dependencies:
- dependency-name: mikey179/vfsstream
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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