deps(rust): update prometheus requirement in /apps/core

Updates the requirements on [prometheus](https://github.com/tikv/rust-prometheus) to permit the latest version.
- [Changelog](https://github.com/tikv/rust-prometheus/blob/master/CHANGELOG.md)
- [Commits](tikv/rust-prometheus@v0.13.0...v0.14.0)

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

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Author: dependabot[bot]