Merge pull request #5105 from lilic/add-prom-operator-dev

communication/slack-config/channels.yaml: Add prometheus-operator-dev

Author: k8s-ci-robot

communication/slack-config/channels.yaml

@@ -281,6 +281,7 @@ channels:
   - name: pr-reviews
   - name: prometheus
   - name: prometheus-operator
+  - name: prometheus-operator-dev
   - name: prow
   - name: prow-alerts
   - name: pt_br-users