Bump prometheus-client from 4.1.0 to 4.2.0

Bumps [prometheus-client](https://github.com/prometheus/client_ruby) from 4.1.0 to 4.2.0.
- [Release notes](https://github.com/prometheus/client_ruby/releases)
- [Changelog](https://github.com/prometheus/client_ruby/blob/main/CHANGELOG.md)
- [Commits](prometheus/client_ruby@v4.1.0...v4.2.0)

---
updated-dependencies:
- dependency-name: prometheus-client
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Gemfile.lock

@@ -457,7 +457,7 @@ GEM
       racc
     pg (1.5.3)
     plek (5.0.0)
-    prometheus-client (4.1.0)
+    prometheus-client (4.2.0)
     prometheus_exporter (2.0.8)
       webrick
     pry (0.14.1)