Update tonic-build requirement from 0.11.0 to 0.12.0

Updates the requirements on [tonic-build](https://github.com/hyperium/tonic) to permit the latest version.
- [Release notes](https://github.com/hyperium/tonic/releases)
- [Changelog](https://github.com/hyperium/tonic/blob/master/CHANGELOG.md)
- [Commits](hyperium/tonic@v0.11.0...v0.12.0)

---
updated-dependencies:
- dependency-name: tonic-build
  dependency-type: direct:production
...

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

Cargo.toml

@@ -72,4 +72,4 @@ tempfile = "3.10.1"
 fake = "2.9.2"
 
 [build-dependencies]
-tonic-build = { version = "0.11.0", features = ["cleanup-markdown"] }
+tonic-build = { version = "0.12.0", features = ["cleanup-markdown"] }