Update prost-build requirement in /rust_pajamax_bench

Updates the requirements on [prost-build](https://github.com/tokio-rs/prost) to permit the latest version.
- [Release notes](https://github.com/tokio-rs/prost/releases)
- [Changelog](https://github.com/tokio-rs/prost/blob/master/CHANGELOG.md)
- [Commits](tokio-rs/prost@v0.13.5...v0.14.0)

---
updated-dependencies:
- dependency-name: prost-build
  dependency-version: 0.14.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

rust_pajamax_bench/Cargo.toml

@@ -15,4 +15,4 @@ prost = "0.13.5"
 
 [build-dependencies]
 pajamax-build = "0.2.0"
-prost-build = "0.13.5"
+prost-build = "0.14.0"