Bump chrono from 0.4.7 to 0.4.8 (#5761)

Bumps [chrono](https://github.com/chronotope/chrono) from 0.4.7 to 0.4.8.
- [Release notes](https://github.com/chronotope/chrono/releases)
- [Changelog](https://github.com/chronotope/chrono/blob/master/CHANGELOG.md)
- [Commits](https://github.com/chronotope/chrono/commits)

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

core/Cargo.toml

@@ -23,7 +23,7 @@ bincode = "1.1.4"
 bs58 = "0.2.5"
 byteorder = "1.3.2"
 bzip2 = "0.3.3"
-chrono = { version = "0.4.7", features = ["serde"] }
+chrono = { version = "0.4.8", features = ["serde"] }
 core_affinity = "0.5.9"
 crc = { version = "1.8.1", optional = true }
 crossbeam-channel = "0.3"