Bump github.com/prometheus/client_golang from 1.18.0 to 1.20.0

Bumps [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang) from 1.18.0 to 1.20.0.
- [Release notes](https://github.com/prometheus/client_golang/releases)
- [Changelog](https://github.com/prometheus/client_golang/blob/main/CHANGELOG.md)
- [Commits](prometheus/client_golang@v1.18.0...v1.20.0)

---
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>

go.mod

@@ -12,7 +12,7 @@ require (
 	github.com/gorilla/mux v1.8.1
 	github.com/gorilla/sessions v1.2.2
 	github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646
-	github.com/prometheus/client_golang v1.18.0
+	github.com/prometheus/client_golang v1.20.0
 	github.com/reef-pi/adafruitio v0.0.0-20171007064130-a3cae37cdd64
 	github.com/reef-pi/drivers v0.0.0-20231021060129-e13db339949d
 	github.com/reef-pi/hal v0.0.0-20220925063527-7d44144f7cf4