Check repo visibility before uploading report

Currently, after the GitHub Action runs CBMC proofs, the proof reports
are compressed and uploaded to GitHub storage for users to download and
view. This commit turns this functionality off if the repository is
private, i.e. it cannot be reached over the public internet.

This fixes #192.

src/cbmc_starter_kit/template-for-ci-workflow/proof_ci.yaml

@@ -156,13 +156,18 @@ jobs:
           EXTERNAL_SAT_SOLVER: kissat
         working-directory: ${{ env.PROOFS_DIR }}
         run: ${{ env.RUN_CBMC_PROOFS_COMMAND }}
+      - name: Check repository visibility
+        shell: bash
+        run: |
+          VIZ="${{ fromJson(toJson(github.event.repository)).visibility }}";
+          echo "REPO_VISIBILITY=${VIZ}" | tee -a "${GITHUB_ENV}";
       - name: Set name for zip artifact with CBMC proof results
         id: artifact
-        if: ${{ env.AWS_CLOUDFRONT_DOMAIN == '' }}
+        if: ${{ env.REPO_VISIBILITY == 'public' }}
         run: |
           echo "name=cbmc_proof_results_${{ fromJson(toJson(github.event.repository)).name }}_$(date +%Y_%m_%d_%H_%M_%S)" >> $GITHUB_OUTPUT
       - name: Create zip artifact with CBMC proof results
-        if: ${{ env.AWS_CLOUDFRONT_DOMAIN == '' }}
+        if: ${{ env.REPO_VISIBILITY == 'public' }}
         shell: bash
         run: |
           FINAL_REPORT_DIR=$PROOFS_DIR/output/latest/html
@@ -171,7 +176,7 @@ jobs:
             && popd \
             && mv $FINAL_REPORT_DIR/${{ steps.artifact.outputs.name }}.zip .
       - name: Upload zip artifact of CBMC proof results to GitHub Actions
-        if: ${{ env.AWS_CLOUDFRONT_DOMAIN == '' }}
+        if: ${{ env.REPO_VISIBILITY == 'public' }}
         uses: actions/upload-artifact@v3
         with:
           name: ${{ steps.artifact.outputs.name }}