include debug option in slack notification

.github/workflows/ubuntu.yml

@@ -72,7 +72,7 @@ jobs:
           payload: |
             {
               "ci": "GitHub Actions",
-              "env": "${{ matrix.os }} / ${{ matrix.test_task }}",
+              "env": "${{ matrix.os }} / ${{ matrix.test_task }}${{ matrix.debug }}",
               "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
               "commit": "${{ github.sha }}",
               "branch": "${{ github.ref }}".split('/').reverse()[0]