Merge pull request #6335 from jpbetz/patch-2

Add sig-api-machinery-cel-dev channel

Author: k8s-ci-robot

communication/slack-config/channels.yaml

@@ -352,6 +352,7 @@ channels:
   - name: shipwright
   - name: shoutouts
   - name: sig-api-machinery
+  - name: sig-api-machinery-cel-dev
   - name: sig-apps
   - name: sig-auth
   - name: sig-autoscaling