Update bytes requirement from 0.5 to 0.6

Updates the requirements on [bytes](https://github.com/tokio-rs/bytes) to permit the latest version.
- [Release notes](https://github.com/tokio-rs/bytes/releases)
- [Changelog](https://github.com/tokio-rs/bytes/blob/master/CHANGELOG.md)
- [Commits](https://github.com/tokio-rs/bytes/compare/v0.5.0...v0.6.0)

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

metrics-exporter-tcp/Cargo.toml

@@ -18,7 +18,7 @@ keywords = ["metrics", "telemetry", "tcp"]
 [dependencies]
 metrics = { version = "0.13.0-alpha.1", path = "../metrics", features = ["std"] }
 metrics-util = { version = "0.4.0-alpha.1", path = "../metrics-util" }
-bytes = "0.5"
+bytes = "0.6"
 crossbeam-channel = "0.5"
 prost = "0.6"
 prost-types = "0.6"