Merge pull request #6504 from kaniini/chore/add-apko-channel

slack-config: add apko channel

Author: k8s-ci-robot

communication/slack-config/channels.yaml

@@ -12,6 +12,7 @@ channels:
   - name: api-priority-and-fairness
   - name: api-reviews
   - name: apisnoop
+  - name: apko
   - name: app-troubleshoot
   - name: archived-sig-release
     archived: true