feat: use download-artifact instead of manually downloading it

This should hopefully work on private repos too!

action.yml

@@ -149,9 +149,10 @@ runs:
       # Ensure the previous step succeeded
       if: steps.previous-report.outcome == 'success'
       with:
-        name: ${{ inputs.artifact-name }}
-        github-token: ${{ inputs.github-token }}
-        run-id: ${{ steps.previous-report.outputs.run-id }}
+        name: report.json
+        # github-token: ${{ inputs.github-token }}
+        repository: jalil/nix-flake-outputs-size
+        run-id: 15
     - name: Create report
       if: inputs.comment-on-pr == 'true' || inputs.generate-artifact == 'true'
       env: