Bump github.com/rabbitmq/cluster-operator from 1.7.0 to 1.8.0

Bumps [github.com/rabbitmq/cluster-operator](https://github.com/rabbitmq/cluster-operator) from 1.7.0 to 1.8.0.
- [Release notes](https://github.com/rabbitmq/cluster-operator/releases)
- [Commits](rabbitmq/cluster-operator@v1.7.0...v1.8.0)

---
updated-dependencies:
- dependency-name: github.com/rabbitmq/cluster-operator
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

go.mod

@@ -11,7 +11,7 @@ require (
 	github.com/michaelklishin/rabbit-hole/v2 v2.10.0
 	github.com/onsi/ginkgo v1.16.4
 	github.com/onsi/gomega v1.13.0
-	github.com/rabbitmq/cluster-operator v1.7.0
+	github.com/rabbitmq/cluster-operator v1.8.0
 	k8s.io/api v0.21.2
 	k8s.io/apimachinery v0.21.2
 	k8s.io/client-go v0.21.2