Update prometheus-client requirement from >=0.20.0 to >=0.25.0

Updates the requirements on [prometheus-client](https://github.com/prometheus/client_python) to permit the latest version.
- [Release notes](https://github.com/prometheus/client_python/releases)
- [Commits](prometheus/client_python@v0.20.0...v0.25.0)

---
updated-dependencies:
- dependency-name: prometheus-client
  dependency-version: 0.25.0
  dependency-type: direct:development
...

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

Author: dependabot[bot]

dev_requirements.txt

@@ -4,6 +4,6 @@ google-auth-httplib2
 google-auth-oauthlib
 APScheduler
 cryptography>=42.0.0
-prometheus_client>=0.20.0
+prometheus_client>=0.25.0
 twine
 build