Remove Slack notification

Author: iamed2

.github/workflows/CI.yml

@@ -137,22 +137,6 @@ jobs:
         with:
           file: lcov.info
 
-  slack:
-    name: Notify Slack Failure
-    needs: test
-    runs-on: ubuntu-latest
-    if: always() && github.event_name == 'schedule'
-    steps:
-      - uses: technote-space/workflow-conclusion-action@v2
-      - uses: voxmedia/github-action-slack-notify-build@v1
-        if: env.WORKFLOW_CONCLUSION == 'failure'
-        with:
-          channel: nightly-dev
-          status: FAILED
-          color: danger
-        env:
-          SLACK_BOT_TOKEN: ${{ secrets.DEV_SLACK_BOT_TOKEN }}
-
   docs:
     name: Documentation
     runs-on: ubuntu-latest