Bump prometheus-client from 0.21.1 to 0.22.0 (#9)

Bumps [prometheus-client](https://github.com/prometheus/client_python) from 0.21.1 to 0.22.0.
- [Release notes](https://github.com/prometheus/client_python/releases)
- [Commits](prometheus/client_python@v0.21.1...v0.22.0)

---
updated-dependencies:
- dependency-name: prometheus-client
  dependency-version: 0.22.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements.txt

@@ -6,6 +6,6 @@ itsdangerous==2.2.0
 Jinja2==3.1.6
 MarkupSafe==3.0.2
 packaging==25.0
-prometheus_client==0.21.1
+prometheus_client==0.22.0
 prometheus_flask_exporter==0.23.2
 Werkzeug==3.1.3