Update hex requirement from 0.3 to 0.4 ...requirements on [hex](https://github.com/KokaKiwi/rust-hex) to permit... - [Release notes](https://github.com/KokaKiwi/rust-hex/releases) - [Commits](https://github.com/KokaKiwi/rust-hex/compare... ...off-by: dependabot[bot] <support@github.com>