fix: write json output to stdout so it can be piped

Signed-off-by: Rahul Vishwakarma <rahulvs2809@gmail.com>

Author: manzil-infinity180

cmd/archivistactl/cmd/search.go

@@ -63,7 +63,7 @@ Digests are expected to be in the form algorithm:digest, for instance: sha256:45
 			if err != nil {
 				return fmt.Errorf("failed to marshal results to JSON: %w", err)
 			}
-			cmd.Println(string(jsonData))
+			fmt.Fprintln(cmd.OutOrStdout(), string(jsonData))
 			return nil
 		}