Simplify Slack notification messages (#2435)

Author: glenn-jocher

.github/workflows/ci-testing.yml

@@ -90,4 +90,4 @@ jobs:
           webhook-type: incoming-webhook
           webhook: ${{ secrets.SLACK_WEBHOOK_URL_YOLO }}
           payload: |
-            text: "<!channel> GitHub Actions error for ${{ github.workflow }} ❌\n\n\n*Repository:* https://github.com/${{ github.repository }}\n*Action:* https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}\n*Author:* ${{ github.actor }}\n*Event:* ${{ github.event_name }}\n"
+            text: "<!subteam^S082BPCRAJ3> *${{ github.workflow }}* ❌ `${{ github.repository }}`  <https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}|*Run*>"