Update prost requirement from 0.11 to 0.12

Updates the requirements on [prost](https://github.com/tokio-rs/prost) to permit the latest version.
- [Release notes](https://github.com/tokio-rs/prost/releases)
- [Commits](tokio-rs/prost@prost-build-0.11.1...v0.12.1)

---
updated-dependencies:
- dependency-name: prost
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

metrics-exporter-tcp/Cargo.toml

@@ -20,7 +20,7 @@ keywords = ["metrics", "telemetry", "tcp"]
 metrics = { version = "^0.21", path = "../metrics" }
 bytes = { version = "1", default-features = false }
 crossbeam-channel = { version = "0.5", default-features = false, features = ["std"] }
-prost = { version = "0.11", default-features = false }
+prost = { version = "0.12", default-features = false }
 prost-types = { version = "0.11", default-features = false, features = ["std"] }
 mio = { version = "0.8", default-features = false, features = ["os-poll", "net"] }
 tracing = { version = "0.1", default-features = false, features = ["attributes"] }

metrics-observer/Cargo.toml

@@ -21,7 +21,7 @@ metrics = { version = "^0.21", path = "../metrics", default-features = false }
 metrics-util = { version = "^0.15", path = "../metrics-util", default-features = false, features = ["summary"] }
 bytes = { version = "1", default-features = false }
 crossbeam-channel = { version = "0.5", default-features = false, features = ["std"] }
-prost = { version = "0.11", default-features = false }
+prost = { version = "0.12", default-features = false }
 prost-types = { version = "0.11", default-features = false }
 tui = { version = "0.19", default-features = false, features = ["termion"] }
 termion = { version = "2", default-features = false }