[Security] Bump fstream from 1.0.11 to 1.0.12 in /build

Bumps [fstream](https://github.com/npm/fstream) from 1.0.11 to 1.0.12. **This update includes a security fix.**
- [Release notes](https://github.com/npm/fstream/releases)
- [Commits](https://github.com/npm/fstream/compare/v1.0.11...v1.0.12

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>