chore(deps): update handlebars requirement from 3.0 to 4.0
chore(deps): update handlebars requirement from 3.0 to 4.0

Updates the requirements on [handlebars](https://github.com/sunng87/handlebars-rust) to permit the latest version.
- [Release notes](https://github.com/sunng87/handlebars-rust/releases)
- [Changelog](https://github.com/sunng87/handlebars-rust/blob/master/CHANGELOG.md)
- [Commits](https://github.com/sunng87/handlebars-rust/compare/v3.0.0...v4.0.0)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
cobalt-org/liquid-rust