Bump prometheus-client from 0.21.0 to 0.21.1

Bumps [prometheus-client](https://github.com/prometheus/client_python) from 0.21.0 to 0.21.1.
- [Release notes](https://github.com/prometheus/client_python/releases)
- [Commits](prometheus/client_python@v0.21.0...v0.21.1)

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

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

pyproject.toml

@@ -10,7 +10,7 @@ readme = "README.md"
 click = "^8.1.7"
 gcn-kafka = "^0.3.3"
 python = "^3.9"
-prometheus-client = "^0.21.0"
+prometheus-client = "^0.21.1"
 boto3 = "^1.35.72"
 # workaround for: https://github.com/python-poetry/poetry-plugin-export/issues/183
 urllib3 = ">=1.25.4,<1.27"