build(deps): 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] <[email protected]>

Author: dependabot[bot]

pyproject.toml

@@ -27,7 +27,7 @@ requires-python = ">=3.9"
 dynamic = ["version"]
 dependencies = [
   "vllm>=0.6.4.post2",
-  "prometheus_client==0.21.0",
+  "prometheus_client==0.21.1",
   "grpcio==1.70.0",
   "grpcio-health-checking==1.70.0",
   "grpcio-reflection==1.70.0",