[Security] Bump stringstream from 0.0.5 to 0.0.6

Bumps [stringstream](https://github.com/mhart/StringStream) from 0.0.5 to 0.0.6. **This update includes security fixes.**
- [Release notes](https://github.com/mhart/StringStream/releases)
- [Commits](mhart/StringStream@v0.0.5...v0.0.6)

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