Decomission Dev Clusters

After all review jobs are skipped on Dev ( #1373 (closed)) we can decomission the following Dev clusters:

• OCP 4.11 ( https://gitlab.com/gitlab-org/distribution/infrastructure/openshift-provisioning/-/issues/41)
• OCP 4.12 ( https://gitlab.com/gitlab-org/distribution/infrastructure/openshift-provisioning/-/issues/46)
• GKE gitlab-operator-dev
• GKE 1.22 gitlab-operator-dev-v122 https://gitlab.com/gitlab-org/distribution/infrastructure/kubernetes-provisioning/-/issues/18

Related CI variables and 1Password entries must also be removed.

Note: This depends on #1373 (closed) being merged into all maintained stable branches