Add email sending step for failed scheduled CI runs

.github/workflows/ci.yml

@@ -54,6 +54,17 @@ jobs:
         if: ${{ github.event_name == 'schedule' }}
         run: npm run test-without-coverage
 
+      - name: Mailgun Action
+        # if: ${{ github.event_name == 'schedule' }} && failure()
+        # Use always() for testing, uncomment above line for real condition
+        if: always()
+        uses: vineetchoudhary/[email protected]
+        with:
+          api-key: ${{ secrets.MAILGUN_API_KEY }}
+          domain: ${{ secrets.MAILGUN_DOMAIN }}
+          to: ${{ secrets.CI_SCHEDULED_FAIL_EMAIL_TO }}
+          subject: 'mwoffliner scheduled CI run FAILED'
+
       - name: Uploading Codecov stats
         uses: codecov/codecov-action@v4
         if: ${{ matrix.node-version == '18.x' }}