feat(hcp-sbom): implement retry logic for downloading Packer release zip

provisioner/hcp-sbom/release_download.go

@@ -241,7 +241,15 @@ func downloadPackerRelease(ctx context.Context, goos, goarch string) (string, er
 	log.Printf("[INFO] Downloading Packer %s for %s/%s...", version, goos, goarch)
 
 	// Download the release zip.
-	zipPath, err := downloadURLToTempFile(ctx, client, zipURL, ".zip")
+	var zipPath string
+	err = retry.Config{
+		Tries: 3,
+		RetryDelay: func() time.Duration {return 5 * time.Second},
+	}.Run(ctx , func(ctx context.Context) error {
+		var e error
+		zipPath, e = downloadURLToTempFile(ctx, client, zipURL, ".zip")
+		return e
+	})
 	if err != nil {
 		return "", fmt.Errorf("failed to download Packer release zip: %w", err)
 	}