Bump github.com/prometheus/client_golang from 1.20.5 to 1.21.0

Bumps [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang) from 1.20.5 to 1.21.0.
- [Release notes](https://github.com/prometheus/client_golang/releases)
- [Changelog](https://github.com/prometheus/client_golang/blob/main/CHANGELOG.md)
- [Commits](prometheus/client_golang@v1.20.5...v1.21.0)

---
updated-dependencies:
- dependency-name: github.com/prometheus/client_golang
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

go.mod

@@ -8,7 +8,7 @@ require (
 	github.com/alecthomas/kingpin/v2 v2.4.0
 	github.com/golang/protobuf v1.5.4
 	github.com/golang/snappy v0.0.4
-	github.com/prometheus/client_golang v1.20.5
+	github.com/prometheus/client_golang v1.21.0
 	github.com/prometheus/client_model v0.6.1
 	github.com/prometheus/common v0.62.0
 	github.com/prometheus/exporter-toolkit v0.13.2

go.sum

@@ -42,8 +42,8 @@ github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f/go.mod h1:qRW
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/prometheus/client_golang v1.20.5 h1:cxppBPuYhUnsO6yo/aoRol4L7q7UFfdm+bR9r+8l63Y=
-github.com/prometheus/client_golang v1.20.5/go.mod h1:PIEt8X02hGcP8JWbeHyeZ53Y/jReSnHgO035n//V5WE=
+github.com/prometheus/client_golang v1.21.0 h1:DIsaGmiaBkSangBgMtWdNfxbMNdku5IK6iNhrEqWvdA=
+github.com/prometheus/client_golang v1.21.0/go.mod h1:U9NM32ykUErtVBxdvD3zfi+EuFkkaBvMb09mIfe0Zgg=
 github.com/prometheus/client_model v0.6.1 h1:ZKSh/rekM+n3CeS952MLRAdFwIKqeY8b62p8ais2e9E=
 github.com/prometheus/client_model v0.6.1/go.mod h1:OrxVMOVHjw3lKMa8+x6HeMGkHMQyHDk9E3jmP2AmGiY=
 github.com/prometheus/common v0.62.0 h1:xasJaQlnWAeyHdUBeGjXmutelfJHWMRr+Fg4QszZ2Io=