build(deps): bump github.com/prometheus/client_golang

Bumps [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang) from 1.10.0 to 1.11.1.
- [Release notes](https://github.com/prometheus/client_golang/releases)
- [Changelog](https://github.com/prometheus/client_golang/blob/main/CHANGELOG.md)
- [Commits](prometheus/client_golang@v1.10.0...v1.11.1)

---
updated-dependencies:
- dependency-name: github.com/prometheus/client_golang
  dependency-type: direct:production
...

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

docker/grafana-promethues/go-demo/go.mod

@@ -2,4 +2,4 @@ module demo
 
 go 1.13
 
-require github.com/prometheus/client_golang v1.10.0
+require github.com/prometheus/client_golang v1.11.1