[Security] Bump handlebars from 4.0.12 to 4.1.0 in /js

Bumps [handlebars](https://github.com/wycats/handlebars.js) from 4.0.12 to 4.1.0. **This update includes security fixes.**
- [Release notes](https://github.com/wycats/handlebars.js/releases)
- [Changelog](https://github.com/wycats/handlebars.js/blob/v4.1.0/release-notes.md)
- [Commits](https://github.com/wycats/handlebars.js/compare/v4.0.12...v4.1.0

)

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