adding a notification for failed testnet nightly tests

Author: signorecello

.github/workflows/testnet.yaml

@@ -136,19 +136,6 @@ jobs:
         run: |
           script -e -c "yarn profile::testnet"
 
-      - name: Send Slack notification on workflow start
-        uses: slackapi/slack-github-action@v2.1.1
-        with:
-          webhook: ${{ secrets.SLACK_WEBHOOK_URL }}
-          webhook-type: incoming-webhook
-          payload: |
-            text: ":rocket: Testnet Tests Started"
-            blocks:
-              - type: "section"
-                text:
-                  type: "mrkdwn"
-                  text: "*Testnet Tests Started*\n:rocket: Workflow: `${{ github.workflow }}`\n:git-branch: Branch: `${{ github.ref_name }}`\n:bust_in_silhouette: Actor: ${{ github.actor }}\n:link: <${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}|View Run>"
-
       - name: Send Slack notification on failure
         if: failure()
         uses: slackapi/slack-github-action@v2.1.1
@@ -161,4 +148,4 @@ jobs:
               - type: "section"
                 text:
                   type: "mrkdwn"
-                  text: "*Testnet Tests Failed*\n:x: Workflow: `${{ github.workflow }}`\n:git-branch: Branch: `${{ github.ref_name }}`\n:bust_in_silhouette: Actor: ${{ github.actor }}\n:link: <${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}|View Run>"
+                  text: "*Testnet Tests Failed*\n:x: Workflow: `${{ github.workflow }}`\n:herb: Branch: `${{ github.ref_name }}`\n:bust_in_silhouette: Actor: ${{ github.actor }}\n:link: <${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}|View Run>"