Verify using post step

.github/actions/verify-debug-artifact-scan-completed/action.yml

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+name: Verify that the best-effort debug artifact scan completed
+description: Verifies that the best-effort debug artifact scan completed successfully during tests
+runs:
+  using: node20
+  main: index.js
+  post: post.js

.github/actions/verify-debug-artifact-scan-completed/index.js

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+// The main step is a no-op, since we can only verify artifact scan completion in the post step.
+console.log("Will verify artifact scan completion in the post step.");

.github/actions/verify-debug-artifact-scan-completed/post.js

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+// Post step - runs after the workflow completes, when artifact scan has finished
+const process = require("process");
+
+const scanFinished = process.env.CODEQL_ACTION_ARTIFACT_SCAN_FINISHED;
+
+if (scanFinished !== "true") {
+  console.error("Error: Best-effort artifact scan did not complete. Expected CODEQL_ACTION_ARTIFACT_SCAN_FINISHED=true");
+  process.exit(1);
+}
+
+console.log("✓ Best-effort artifact scan completed successfully");