Bump hex from 0.3.2 to 0.4.0

Bumps [hex](https://github.com/KokaKiwi/rust-hex) from 0.3.2 to 0.4.0.
- [Release notes](https://github.com/KokaKiwi/rust-hex/releases)
- [Commits](KokaKiwi/rust-hex@v0.3.2...v0.4.0)

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

Author: dependabot-preview[bot]

Cargo.lock

@@ -19,7 +19,7 @@ chrono = "0.4"
 rmp-serde = "0.14.0"
 semver = "0.9"
 ring = "0.16.9"
-hex = "0.3.2"
+hex = "0.4.0"
 regex = "1"
 lazy_static = "1"
 reqwest = "0.9"